Abstract image of a woman sitting on books and studying on a laptop

Debugging WordPress

Brecht Ryckaert, profile picture
Brecht Ryckaert

The document discusses debugging WordPress websites. It provides tips on examining server logs to find errors, enabling WP_DEBUG in wp-config.php to output debugging information, and using the wp-cli command line interface to manage plugins, themes and check for errors. Common errors like "headers already sent" are presented along with solutions. The presenter's contact details and promise to share the slides on social media are listed at the end.

Internet
1 of 42
Download to read offline
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
D E B U G G I N G W O R D P R E S S B R E C H T RY C K A E R T
B R E C H T RY C K A E R T • Works at combell.com • WP user since 1.5 • Passionate about WordPress Security & Performance
 
 @brechtryckaert
 brechtryckaert.com
W H E N L A U N C H I N G Y O U R N E W W E B S I T E
O R W H E N U P D AT I N G Y O U R P L U G I N S O R T H E M E S
… O R E V E N M I G R AT I N G Y O U R W E B S I T E …
Debugging WordPress
Debugging WordPress
W H O ’ S E X P E R I E N C E D T H I S B E F O R E ?
Debugging WordPress
T W O K I N D S O F 
 E R R O R C O D E S …
4 0 0 - C O D E S 
 5 0 0 - C O D E S
4 0 0 - C O D E S 
 5 0 0 - C O D E S You stuffed up (client errors) Your server stuffed up (server errors)
400 Bad Request 401 Unauthorized (RFC 7235) 402 Payment Required 403 Forbidden 404 Not Found 405 Method Not Allowed …
500 Internal Server Error 501 Not Implemented 502 Bad Gateway 503 Service Unavailable 504 Gateway Timeout …
H O W T O D E B U G ?
- S E R V E R L O G S 
 - W P _ D E B U G 
 - W P - C L I
S E R V E R L O G S
T Y P E S O F E R R O R S I N T H E L O G S • FATAL ERROR • WARNING/NOTICE • LIMIT-RELATED
[Sat Feb 10 02:05:22.490389 2018] [error] [pid 5740] mod_proxy_fcgi.c(954): (70007)The timeout specified has expired: [client 141.101.77.82:32531] AH01075: Error dispatching request to : (polling) [Sat Feb 10 03:42:55.356581 2018] [error] [pid 34419] mod_authz_core.c(873): [client 176.62.169.28:27736] AH01630: client denied by server configuration: /data/sites/web/somewebsite.com/.user.ini [Sat Feb 10 10:50:24.838424 2018] [error] [pid 41100] mod_proxy_fcgi.c(954): (70007)The timeout specified has expired: [client 162.158.111.75:24677] AH01075: Error dispatching request to : (polling) [Sat Feb 10 10:50:36.741167 2018] [error] [pid 48392] apache2_util.c(271): [client 172.68.65.254:35087] [client 172.68.65.254] ModSecurity: Access denied with code 403 (phase 2). Matched phrase "SemrushBot" at REQUEST_HEADERS:User-Agent. [file "/usr/local/httpd/conf/modsecurity-crs/activated-rules/modsecurity_crs_35_bad_robots.conf"] [line "20"] [id "990002"] [rev "2"] [msg "Request Indicates a Security Scanner Scanned the Site"] [data "mozilla/5.0 (compatible; semrushb ot/1.2~bl; +http://www.semrush.com/bot.html)"] [severity "CRITICAL"] [ver "OWASP_CRS/2.2.9"] [maturity "9"] [accuracy "9"] [tag "OWASP_CRS/AUTOMATION/SECURITY_SCANNER"] [tag "WASCTC/WASC-21"] [tag "OWASP_TOP_10/A7"] [tag "PCI/6.5.10"] [h ostname “www.somewebsite.com”] [uri "/tag/romeinen/"] [unique_id "Wn7AbE4XLPnYH7fIxTBlGwAAAcY"]
[Sat Feb 10 02:05:22.490389 2018] [error] [pid 5740] mod_proxy_fcgi.c(954): (70007)The timeout specified has expired: [client 141.101.77.82:32531] AH01075: Error dispatching request to : (polling) [Sat Feb 10 03:42:55.356581 2018] [error] [pid 34419] mod_authz_core.c(873): [client 176.62.169.28:27736] AH01630: client denied by server configuration:/data/sites/web/somewebsite.com/.user.ini [Sat Feb 10 10:50:24.838424 2018] [error] [pid 41100] mod_proxy_fcgi.c(954): (70007)The timeout specified has expired: [client 162.158.111.75:24677] AH01075: Error dispatching request to : (polling) [Sat Feb 10 10:50:36.741167 2018] [error] [pid 48392] apache2_util.c(271): [client 172.68.65.254:35087] [client 172.68.65.254] ModSecurity: Access denied with code 403 (phase 2). Matched phrase "SemrushBot" at REQUEST_HEADERS:User-Agent. [file "/usr/local/httpd/conf/modsecurity-crs/activated-rules/modsecurity_crs_35_bad_robots.conf"] [line "20"] [id "990002"] [rev "2"] [msg "Request Indicates a Security Scanner Scanned the Site"] [data "mozilla/5.0 (compatible; semrushb ot/1.2~bl; +http://www.semrush.com/bot.html)"] [severity "CRITICAL"] [ver "OWASP_CRS/2.2.9"] [maturity "9"] [accuracy "9"] [tag "OWASP_CRS/AUTOMATION/SECURITY_SCANNER"] [tag "WASCTC/WASC-21"] [tag "OWASP_TOP_10/A7"] [tag "PCI/6.5.10"] [h ostname “www.somewebsite.com”] [uri "/tag/romeinen/"] [unique_id "Wn7AbE4XLPnYH7fIxTBlGwAAAcY"]
[Sat Feb 10 02:05:22.490389 2018] [error] [pid 5740] mod_proxy_fcgi.c(954): (70007)The timeout specified has expired: [client 141.101.77.82:32531] AH01075: Error dispatching request to : (polling) [Sat Feb 10 03:42:55.356581 2018] [error] [pid 34419] mod_authz_core.c(873): [client 176.62.169.28:27736] AH01630: client denied by server configuration: /data/sites/web/somewebsite.com/.user.ini [Sat Feb 10 10:50:24.838424 2018] [error] [pid 41100] mod_proxy_fcgi.c(954): (70007)The timeout specified has expired: [client 162.158.111.75:24677] AH01075: Error dispatching request to : (polling) [Sat Feb 10 10:50:36.741167 2018] [error] [pid 48392] apache2_util.c(271): [client 172.68.65.254:35087] [client 172.68.65.254] ModSecurity: Access denied with code 403 (phase 2). Matched phrase "SemrushBot" at REQUEST_HEADERS:User-Agent. [file "/usr/local/httpd/conf/modsecurity-crs/activated-rules/modsecurity_crs_35_bad_robots.conf"] [line "20"] [id "990002"] [rev "2"] [msg "Request Indicates a Security Scanner Scanned the Site"] [data "mozilla/5.0 (compatible; semrushb ot/1.2~bl; +http://www.semrush.com/bot.html)"] [severity "CRITICAL"] [ver "OWASP_CRS/2.2.9"] [maturity "9"] [accuracy "9"] [tag "OWASP_CRS/AUTOMATION/SECURITY_SCANNER"] [tag "WASCTC/WASC-21"] [tag "OWASP_TOP_10/A7"] [tag "PCI/6.5.10"] [h ostname “www.somewebsite.com”] [uri "/tag/romeinen/"] [unique_id "Wn7AbE4XLPnYH7fIxTBlGwAAAcY"]
Tue Jan 16 15:10:55.316779 2018] [error] [pid 6002] mod_proxy_fcgi.c(848): [client 178.119.78.83:63467] AH01071: Got error 'PHP message: PHP Fatal error:  Uncaught Error: Call to undefined method SitePress::is_display_as_translated_taxonomy() in /data/sites/web/somewebsite/ www/wp-content/plugins/woocommerce-multilingual/inc/class-wcml-dependencies.php:365nStack trace:n#0 /data/sites/web/somewebsite/www/wp-includes/class-wp-hook.php(286): WCML_Dependencies->check_wpml_config('')n#1 /data/sites/web/somewebsite/www/wp-includes/ class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array)n#2 /data/sites/web/somewebsite/ www/wp-includes/plugin.php(453): WP_Hook->do_action(Array)n#3 /data/sites/web/somewebsite/ www/wp-settings.php(450): do_action('init')n#4 /data/sites/web/somewebsite/www/wp- config.php(83): require_once('/data/sites/web...')n#5 /data/sites/web/somewebsite/www/wp- load.php(37): require_once('/data/sites/web...')n#6 /data/sites/web/somewebsite/www/wp-admin/ admin-ajax.php(22): require_once('/data/sites/web...')n#7 {main}n  thrown in /data/sites/web/ somewebsite/www/wp-content/plugins/woocommerce-multilingua...n'
Tue Jan 16 15:10:55.316779 2018] [error] [pid 6002] mod_proxy_fcgi.c(848): [client 178.119.78.83:63467] AH01071: Got error 'PHP message: PHP Fatal error:  Uncaught Error: Call to undefined method SitePress::is_display_as_translated_taxonomy() in /data/sites/web/ somewebsite/www/wp-content/plugins/woocommerce-multilingual/inc/class-wcml-dependencies.php: 365nStack trace:n#0 /data/sites/web/somewebsite/www/wp-includes/class-wp-hook.php(286): WCML_Dependencies->check_wpml_config('')n#1 /data/sites/web/somewebsite/www/wp-includes/ class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array)n#2 /data/sites/web/somewebsite/ www/wp-includes/plugin.php(453): WP_Hook->do_action(Array)n#3 /data/sites/web/somewebsite/ www/wp-settings.php(450): do_action('init')n#4 /data/sites/web/somewebsite/www/wp- config.php(83): require_once('/data/sites/web...')n#5 /data/sites/web/somewebsite/www/wp- load.php(37): require_once('/data/sites/web...')n#6 /data/sites/web/somewebsite/www/wp-admin/ admin-ajax.php(22): require_once('/data/sites/web...')n#7 {main}n  thrown in /data/sites/web/ somewebsite/www/wp-content/plugins/woocommerce-multilingua...n'
T H E P O W E R O F W P _ D E B U G
W P _ D E B U G In wp-config.php: define( 'WP_DEBUG', false ); Enable debugging: define( 'WP_DEBUG', true );
W P _ D E B U G Extra statements: define('WP_DEBUG_LOG', true); Creates logfile in: /wp-content/debug.log
W P _ D E B U G Prevent public displaying of errors: define('WP_DEBUG_DISPLAY', false);
W P _ D E B U G Ideal setup: define('WP_DEBUG', true);
 define('WP_DEBUG_LOG', true);
 define('WP_DEBUG_DISPLAY', false);
A D D I N G W P - C L I 
 T O Y O U R T O O L K I T
W P - C L I wp plugin list
 wp plugin deactivate
 wp plugin activate wp theme list
 wp theme deactivate
 wp theme activate wp checksum core
 wp checksum plugin (from version 1.5)
W P T H E M E L I S T R E S U LT Parse error: syntax error, unexpected '$z9973449' (T_VARIABLE) in /data/sites/web/somewebsite/ www/wp-includes/post-template.php on line 1 Warning: array_splice() expects parameter 1 to be array, string given in /data/sites/web/somewebsite/ www/wp-content/plugins/akismet/favicon_316779.ico(105) : eval()'d code(165) : eval()'d code(202) : eval()'d code on line 206 Warning: Invalid argument supplied for foreach() in /data/sites/web/somewebsite/www/wp-content/ plugins/akismet/favicon_316779.ico(105) : eval()'d code(165) : eval()'d code(202) : eval()'d code on line 207
W P T H E M E L I S T R E S U LT Parse error: syntax error, unexpected '$z9973449' (T_VARIABLE) in /data/sites/web/somewebsite/ www/wp-includes/post-template.php on line 1 Warning: array_splice() expects parameter 1 to be array, string given in /data/sites/web/somewebsite/ www/wp-content/plugins/akismet/favicon_316779.ico(105) : eval()'d code(165) : eval()'d code(202) : eval()'d code on line 206 Warning: Invalid argument supplied for foreach() in /data/sites/web/somewebsite/www/wp-content/ plugins/akismet/favicon_316779.ico(105) : eval()'d code(165) : eval()'d code(202) : eval()'d code on line 207
T Y P I C A L E R R O R S 
 A N D H O W T O F I X T H E M
Debugging WordPress
Debugging WordPress
Debugging WordPress
Debugging WordPress
Warning: Cannot modify header information - headers already sent by (output started at /data/sites/ web/somewebsite/www/wp-settings.php:84) in /data/sites/web/somewebsite/www/wp-includes/ option.php on line 920
Warning: Cannot modify header information - headers already sent by (output started at /data/sites/web/somewebsite/www/wp-settings.php:84) in /data/sites/web/ somewebsite/www/wp-includes/option.php on line 920
Warning: Cannot modify header information - headers already sent by (output started at /data/sites/web/somewebsite/www/wp-settings.php:84) in /data/sites/web/ somewebsite/www/wp-includes/option.php on line 920 Fix: 
 Enabe output_buffering
Q U E S T I O N S ?
T H A N K Y O U ! 
 S L I D E S W I L L B E T W E E T E D O N 
 @ B R E C H RY C K A E R T 
 
 A N D P U B L I S H E D O N H T T P S : / / B R E C H T RY C K A E R T. C O M

More Related Content

PDF
WordCamp Antwerp - 3/3/2018 - Debugging WordPress by Brecht Ryckaert
Brecht Ryckaert
 
PDF
Systems and methods for visual presentation and selection of ivr menu
Tal Lavian Ph.D.
 
PDF
Interofficeag.ch
smithamos
 
PPT
Windows update
yvesca
 
TXT
Saii log
rondk May
 
PDF
Marketing pra fotógrafos
Fantoches de Luz
 
DOCX
CM_TX_Devices
Jeremiah Cargill
 
PDF
MANUAL PHOTOSHOP CS5
autonomo
 
WordCamp Antwerp - 3/3/2018 - Debugging WordPress by Brecht Ryckaert
Brecht Ryckaert
 
Systems and methods for visual presentation and selection of ivr menu
Tal Lavian Ph.D.
 
Interofficeag.ch
smithamos
 
Windows update
yvesca
 
Saii log
rondk May
 
Marketing pra fotógrafos
Fantoches de Luz
 
CM_TX_Devices
Jeremiah Cargill
 
MANUAL PHOTOSHOP CS5
autonomo
 

Similar to Debugging WordPress (20)

PDF
Integrating WordPress With Web APIs
randyhoyt
 
PDF
Integrating WordPress With Web APIs
randyhoyt
 
PPTX
Malware Detection with OSSEC HIDS - OSSECCON 2014
Santiago Bassett
 
PDF
ChatOps: Automating your Company with HipChat, Bitbucket and JIRA Service Desk
Atlassian
 
PPS
Hacking Client Side Insecurities
amiable_indian
 
PDF
Smashing the stats for fun (and profit)
Security B-Sides
 
PDF
OAuth 2.0
Uwe Friedrichsen
 
PPTX
3DConsulting_Presentation
Joseph Baca
 
PPTX
Building a WiFi Hotspot with NodeJS: Cisco Meraki - ExCap API
Cisco DevNet
 
PDF
Logstash for SEO: come monitorare i Log del Web Server in realtime
Andrea Cardinale
 
PDF
Minor Mistakes In Web Portals
msobiegraj
 
PPTX
Platform agnostic information systems development
Mark Jayson Fuentes
 
PPTX
Real World Lessons on the Pain Points of Node.js Applications
Ben Hall
 
PPT
Derek Pearcy - Reading Users' Minds For Fun And Profit
bolt peters
 
PDF
OAuth 2.0 – A standard is coming of age by Uwe Friedrichsen
Codemotion
 
PPT
Widget Summit 2008
Volkan Unsal
 
PDF
[convergese] Adaptive Images in Responsive Web Design
Christopher Schmitt
 
PPTX
Real
Joshua Silver
 
PPTX
Hacking Wordpress Plugins
Larry Cashdollar
 
PPTX
Webinar: Extend The Power of The ForgeRock Identity Platform Through Scripting
ForgeRock
 
Integrating WordPress With Web APIs
randyhoyt
 
Integrating WordPress With Web APIs
randyhoyt
 
Malware Detection with OSSEC HIDS - OSSECCON 2014
Santiago Bassett
 
ChatOps: Automating your Company with HipChat, Bitbucket and JIRA Service Desk
Atlassian
 
Hacking Client Side Insecurities
amiable_indian
 
Smashing the stats for fun (and profit)
Security B-Sides
 
OAuth 2.0
Uwe Friedrichsen
 
3DConsulting_Presentation
Joseph Baca
 
Building a WiFi Hotspot with NodeJS: Cisco Meraki - ExCap API
Cisco DevNet
 
Logstash for SEO: come monitorare i Log del Web Server in realtime
Andrea Cardinale
 
Minor Mistakes In Web Portals
msobiegraj
 
Platform agnostic information systems development
Mark Jayson Fuentes
 
Real World Lessons on the Pain Points of Node.js Applications
Ben Hall
 
Derek Pearcy - Reading Users' Minds For Fun And Profit
bolt peters
 
OAuth 2.0 – A standard is coming of age by Uwe Friedrichsen
Codemotion
 
Widget Summit 2008
Volkan Unsal
 
[convergese] Adaptive Images in Responsive Web Design
Christopher Schmitt
 
Real
Joshua Silver
 
Hacking Wordpress Plugins
Larry Cashdollar
 
Webinar: Extend The Power of The ForgeRock Identity Platform Through Scripting
ForgeRock
 
Ad

More from Brecht Ryckaert (13)

PDF
Using WordPress as a Static Site Generator
Brecht Ryckaert
 
PDF
The Anatomy Of A Hack - WordCamp Sofia 2018
Brecht Ryckaert
 
PDF
Scaling WordPress On A Small Budget
Brecht Ryckaert
 
PDF
WordPress Meetup Ieper - 15/03/2018 - WordPress Security Best Practices
Brecht Ryckaert
 
PDF
WordPress Security - A Top Down Approach
Brecht Ryckaert
 
PDF
WordPress Performantie Optimalisatie
Brecht Ryckaert
 
PDF
WordPress Performance optimization
Brecht Ryckaert
 
PPTX
WordPress Security - Battening down the hatches
Brecht Ryckaert
 
PPTX
Speeding up WordPress
Brecht Ryckaert
 
PDF
WordPress Security
Brecht Ryckaert
 
PPTX
De valkuilen bij het migreren of publiceren van je WordPress website
Brecht Ryckaert
 
PPT
Combell Academy - Exchange 2010
Brecht Ryckaert
 
PPT
Presentatie Ebook
Brecht Ryckaert
 
Using WordPress as a Static Site Generator
Brecht Ryckaert
 
The Anatomy Of A Hack - WordCamp Sofia 2018
Brecht Ryckaert
 
Scaling WordPress On A Small Budget
Brecht Ryckaert
 
WordPress Meetup Ieper - 15/03/2018 - WordPress Security Best Practices
Brecht Ryckaert
 
WordPress Security - A Top Down Approach
Brecht Ryckaert
 
WordPress Performantie Optimalisatie
Brecht Ryckaert
 
WordPress Performance optimization
Brecht Ryckaert
 
WordPress Security - Battening down the hatches
Brecht Ryckaert
 
Speeding up WordPress
Brecht Ryckaert
 
WordPress Security
Brecht Ryckaert
 
De valkuilen bij het migreren of publiceren van je WordPress website
Brecht Ryckaert
 
Combell Academy - Exchange 2010
Brecht Ryckaert
 
Presentatie Ebook
Brecht Ryckaert
 
Ad

Recently uploaded (20)

PPTX
Database Information System - Management Information System
faizhossain3
 
PDF
Exploring VPS Hosting Trends for SMBs in 2025
Liquid Web
 
PPTX
artificialintelligenceai1-copy-210604123353.pptx
b45r14
 
PPTX
Internet Safety for Seniors presentation
mwnorman1
 
PDF
Containerization lab dddddddddddddddmanual.pdf
muler161921
 
PDF
Uptota Investor Deck - Where Africa Meets Blockchain
jjc123linkedin
 
PDF
si manuel quezon at mga nagawa sa bansang pilipinas
LizaDeVeraFloresLaya
 
PDF
mera desh ae watn.(a source of motivation and patriotism to the youth of the ...
DtMalhonSharma
 
PDF
Exploring The Internet Of Things(IOT).ppt
rakeshk19831911
 
PPTX
module 1-Part 1.pptxdddddddddddddddddddddddddddddddddddd
KevinSeelu
 
PDF
The Ikigai Template _ Recalibrate How You Spend Your Time.pdf
KinchitJain2
 
PDF
Alethe Consulting Corporate Profile and Solution Aproach
debashisrakshit2025
 
PDF
The Evolution of Traditional to New Media .pdf
NIKKODENSMIRO
 
PDF
📍 LABUAN4D EXCLUSIVE SERVER STAR GAMING ASIA NO.1 TERPOPULER DI INDONESIA ! 🌟
alexiskandar061
 
PPTX
curriculumandpedagogyinearlychildhoodcurriculum-171021103104 - Copy.pptx
HeneszaAvenido1
 
PPTX
AI_Cyberattack_Solutions AI AI AI AI .pptx
zayadeen2003
 
PDF
Smart Home Technology for Health Monitoring (www.kiu.ac.ug)
publication11
 
PPTX
Cyber Hygine IN organizations in MSME or
paramkiet
 
PPTX
Layers_of_the_Earth_Grade7.pptx class by
varadhanvara05
 
PPTX
Top Website Bugs That Hurt User Experience – And How Expert Web Design Fixes
e-Definers Technology
 
Database Information System - Management Information System
faizhossain3
 
Exploring VPS Hosting Trends for SMBs in 2025
Liquid Web
 
artificialintelligenceai1-copy-210604123353.pptx
b45r14
 
Internet Safety for Seniors presentation
mwnorman1
 
Containerization lab dddddddddddddddmanual.pdf
muler161921
 
Uptota Investor Deck - Where Africa Meets Blockchain
jjc123linkedin
 
si manuel quezon at mga nagawa sa bansang pilipinas
LizaDeVeraFloresLaya
 
mera desh ae watn.(a source of motivation and patriotism to the youth of the ...
DtMalhonSharma
 
Exploring The Internet Of Things(IOT).ppt
rakeshk19831911
 
module 1-Part 1.pptxdddddddddddddddddddddddddddddddddddd
KevinSeelu
 
The Ikigai Template _ Recalibrate How You Spend Your Time.pdf
KinchitJain2
 
Alethe Consulting Corporate Profile and Solution Aproach
debashisrakshit2025
 
The Evolution of Traditional to New Media .pdf
NIKKODENSMIRO
 
📍 LABUAN4D EXCLUSIVE SERVER STAR GAMING ASIA NO.1 TERPOPULER DI INDONESIA ! 🌟
alexiskandar061
 
curriculumandpedagogyinearlychildhoodcurriculum-171021103104 - Copy.pptx
HeneszaAvenido1
 
AI_Cyberattack_Solutions AI AI AI AI .pptx
zayadeen2003
 
Smart Home Technology for Health Monitoring (www.kiu.ac.ug)
publication11
 
Cyber Hygine IN organizations in MSME or
paramkiet
 
Layers_of_the_Earth_Grade7.pptx class by
varadhanvara05
 
Top Website Bugs That Hurt User Experience – And How Expert Web Design Fixes
e-Definers Technology
 

Debugging WordPress

  • 1. D E B U G G I N G W O R D P R E S S B R E C H T RY C K A E R T
  • 2. B R E C H T RY C K A E R T • Works at combell.com • WP user since 1.5 • Passionate about WordPress Security & Performance
 
 @brechtryckaert
 brechtryckaert.com
  • 3. W H E N L A U N C H I N G Y O U R N E W W E B S I T E
  • 4. O R W H E N U P D AT I N G Y O U R P L U G I N S O R T H E M E S
  • 5. … O R E V E N M I G R AT I N G Y O U R W E B S I T E …
  • 8. W H O ’ S E X P E R I E N C E D T H I S B E F O R E ?
  • 10. T W O K I N D S O F 
 E R R O R C O D E S …
  • 11. 4 0 0 - C O D E S 
 5 0 0 - C O D E S
  • 12. 4 0 0 - C O D E S 
 5 0 0 - C O D E S You stuffed up (client errors) Your server stuffed up (server errors)
  • 13. 400 Bad Request 401 Unauthorized (RFC 7235) 402 Payment Required 403 Forbidden 404 Not Found 405 Method Not Allowed …
  • 14. 500 Internal Server Error 501 Not Implemented 502 Bad Gateway 503 Service Unavailable 504 Gateway Timeout …
  • 15. H O W T O D E B U G ?
  • 16. - S E R V E R L O G S 
 - W P _ D E B U G 
 - W P - C L I
  • 17. S E R V E R L O G S
  • 18. T Y P E S O F E R R O R S I N T H E L O G S • FATAL ERROR • WARNING/NOTICE • LIMIT-RELATED
  • 19. [Sat Feb 10 02:05:22.490389 2018] [error] [pid 5740] mod_proxy_fcgi.c(954): (70007)The timeout specified has expired: [client 141.101.77.82:32531] AH01075: Error dispatching request to : (polling) [Sat Feb 10 03:42:55.356581 2018] [error] [pid 34419] mod_authz_core.c(873): [client 176.62.169.28:27736] AH01630: client denied by server configuration: /data/sites/web/somewebsite.com/.user.ini [Sat Feb 10 10:50:24.838424 2018] [error] [pid 41100] mod_proxy_fcgi.c(954): (70007)The timeout specified has expired: [client 162.158.111.75:24677] AH01075: Error dispatching request to : (polling) [Sat Feb 10 10:50:36.741167 2018] [error] [pid 48392] apache2_util.c(271): [client 172.68.65.254:35087] [client 172.68.65.254] ModSecurity: Access denied with code 403 (phase 2). Matched phrase "SemrushBot" at REQUEST_HEADERS:User-Agent. [file "/usr/local/httpd/conf/modsecurity-crs/activated-rules/modsecurity_crs_35_bad_robots.conf"] [line "20"] [id "990002"] [rev "2"] [msg "Request Indicates a Security Scanner Scanned the Site"] [data "mozilla/5.0 (compatible; semrushb ot/1.2~bl; +http://www.semrush.com/bot.html)"] [severity "CRITICAL"] [ver "OWASP_CRS/2.2.9"] [maturity "9"] [accuracy "9"] [tag "OWASP_CRS/AUTOMATION/SECURITY_SCANNER"] [tag "WASCTC/WASC-21"] [tag "OWASP_TOP_10/A7"] [tag "PCI/6.5.10"] [h ostname “www.somewebsite.com”] [uri "/tag/romeinen/"] [unique_id "Wn7AbE4XLPnYH7fIxTBlGwAAAcY"]
  • 20. [Sat Feb 10 02:05:22.490389 2018] [error] [pid 5740] mod_proxy_fcgi.c(954): (70007)The timeout specified has expired: [client 141.101.77.82:32531] AH01075: Error dispatching request to : (polling) [Sat Feb 10 03:42:55.356581 2018] [error] [pid 34419] mod_authz_core.c(873): [client 176.62.169.28:27736] AH01630: client denied by server configuration:/data/sites/web/somewebsite.com/.user.ini [Sat Feb 10 10:50:24.838424 2018] [error] [pid 41100] mod_proxy_fcgi.c(954): (70007)The timeout specified has expired: [client 162.158.111.75:24677] AH01075: Error dispatching request to : (polling) [Sat Feb 10 10:50:36.741167 2018] [error] [pid 48392] apache2_util.c(271): [client 172.68.65.254:35087] [client 172.68.65.254] ModSecurity: Access denied with code 403 (phase 2). Matched phrase "SemrushBot" at REQUEST_HEADERS:User-Agent. [file "/usr/local/httpd/conf/modsecurity-crs/activated-rules/modsecurity_crs_35_bad_robots.conf"] [line "20"] [id "990002"] [rev "2"] [msg "Request Indicates a Security Scanner Scanned the Site"] [data "mozilla/5.0 (compatible; semrushb ot/1.2~bl; +http://www.semrush.com/bot.html)"] [severity "CRITICAL"] [ver "OWASP_CRS/2.2.9"] [maturity "9"] [accuracy "9"] [tag "OWASP_CRS/AUTOMATION/SECURITY_SCANNER"] [tag "WASCTC/WASC-21"] [tag "OWASP_TOP_10/A7"] [tag "PCI/6.5.10"] [h ostname “www.somewebsite.com”] [uri "/tag/romeinen/"] [unique_id "Wn7AbE4XLPnYH7fIxTBlGwAAAcY"]
  • 21. [Sat Feb 10 02:05:22.490389 2018] [error] [pid 5740] mod_proxy_fcgi.c(954): (70007)The timeout specified has expired: [client 141.101.77.82:32531] AH01075: Error dispatching request to : (polling) [Sat Feb 10 03:42:55.356581 2018] [error] [pid 34419] mod_authz_core.c(873): [client 176.62.169.28:27736] AH01630: client denied by server configuration: /data/sites/web/somewebsite.com/.user.ini [Sat Feb 10 10:50:24.838424 2018] [error] [pid 41100] mod_proxy_fcgi.c(954): (70007)The timeout specified has expired: [client 162.158.111.75:24677] AH01075: Error dispatching request to : (polling) [Sat Feb 10 10:50:36.741167 2018] [error] [pid 48392] apache2_util.c(271): [client 172.68.65.254:35087] [client 172.68.65.254] ModSecurity: Access denied with code 403 (phase 2). Matched phrase "SemrushBot" at REQUEST_HEADERS:User-Agent. [file "/usr/local/httpd/conf/modsecurity-crs/activated-rules/modsecurity_crs_35_bad_robots.conf"] [line "20"] [id "990002"] [rev "2"] [msg "Request Indicates a Security Scanner Scanned the Site"] [data "mozilla/5.0 (compatible; semrushb ot/1.2~bl; +http://www.semrush.com/bot.html)"] [severity "CRITICAL"] [ver "OWASP_CRS/2.2.9"] [maturity "9"] [accuracy "9"] [tag "OWASP_CRS/AUTOMATION/SECURITY_SCANNER"] [tag "WASCTC/WASC-21"] [tag "OWASP_TOP_10/A7"] [tag "PCI/6.5.10"] [h ostname “www.somewebsite.com”] [uri "/tag/romeinen/"] [unique_id "Wn7AbE4XLPnYH7fIxTBlGwAAAcY"]
  • 22. Tue Jan 16 15:10:55.316779 2018] [error] [pid 6002] mod_proxy_fcgi.c(848): [client 178.119.78.83:63467] AH01071: Got error 'PHP message: PHP Fatal error:  Uncaught Error: Call to undefined method SitePress::is_display_as_translated_taxonomy() in /data/sites/web/somewebsite/ www/wp-content/plugins/woocommerce-multilingual/inc/class-wcml-dependencies.php:365nStack trace:n#0 /data/sites/web/somewebsite/www/wp-includes/class-wp-hook.php(286): WCML_Dependencies->check_wpml_config('')n#1 /data/sites/web/somewebsite/www/wp-includes/ class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array)n#2 /data/sites/web/somewebsite/ www/wp-includes/plugin.php(453): WP_Hook->do_action(Array)n#3 /data/sites/web/somewebsite/ www/wp-settings.php(450): do_action('init')n#4 /data/sites/web/somewebsite/www/wp- config.php(83): require_once('/data/sites/web...')n#5 /data/sites/web/somewebsite/www/wp- load.php(37): require_once('/data/sites/web...')n#6 /data/sites/web/somewebsite/www/wp-admin/ admin-ajax.php(22): require_once('/data/sites/web...')n#7 {main}n  thrown in /data/sites/web/ somewebsite/www/wp-content/plugins/woocommerce-multilingua...n'
  • 23. Tue Jan 16 15:10:55.316779 2018] [error] [pid 6002] mod_proxy_fcgi.c(848): [client 178.119.78.83:63467] AH01071: Got error 'PHP message: PHP Fatal error:  Uncaught Error: Call to undefined method SitePress::is_display_as_translated_taxonomy() in /data/sites/web/ somewebsite/www/wp-content/plugins/woocommerce-multilingual/inc/class-wcml-dependencies.php: 365nStack trace:n#0 /data/sites/web/somewebsite/www/wp-includes/class-wp-hook.php(286): WCML_Dependencies->check_wpml_config('')n#1 /data/sites/web/somewebsite/www/wp-includes/ class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array)n#2 /data/sites/web/somewebsite/ www/wp-includes/plugin.php(453): WP_Hook->do_action(Array)n#3 /data/sites/web/somewebsite/ www/wp-settings.php(450): do_action('init')n#4 /data/sites/web/somewebsite/www/wp- config.php(83): require_once('/data/sites/web...')n#5 /data/sites/web/somewebsite/www/wp- load.php(37): require_once('/data/sites/web...')n#6 /data/sites/web/somewebsite/www/wp-admin/ admin-ajax.php(22): require_once('/data/sites/web...')n#7 {main}n  thrown in /data/sites/web/ somewebsite/www/wp-content/plugins/woocommerce-multilingua...n'
  • 24. T H E P O W E R O F W P _ D E B U G
  • 25. W P _ D E B U G In wp-config.php: define( 'WP_DEBUG', false ); Enable debugging: define( 'WP_DEBUG', true );
  • 26. W P _ D E B U G Extra statements: define('WP_DEBUG_LOG', true); Creates logfile in: /wp-content/debug.log
  • 27. W P _ D E B U G Prevent public displaying of errors: define('WP_DEBUG_DISPLAY', false);
  • 28. W P _ D E B U G Ideal setup: define('WP_DEBUG', true);
 define('WP_DEBUG_LOG', true);
 define('WP_DEBUG_DISPLAY', false);
  • 29. A D D I N G W P - C L I 
 T O Y O U R T O O L K I T
  • 30. W P - C L I wp plugin list
 wp plugin deactivate
 wp plugin activate wp theme list
 wp theme deactivate
 wp theme activate wp checksum core
 wp checksum plugin (from version 1.5)
  • 31. W P T H E M E L I S T R E S U LT Parse error: syntax error, unexpected '$z9973449' (T_VARIABLE) in /data/sites/web/somewebsite/ www/wp-includes/post-template.php on line 1 Warning: array_splice() expects parameter 1 to be array, string given in /data/sites/web/somewebsite/ www/wp-content/plugins/akismet/favicon_316779.ico(105) : eval()'d code(165) : eval()'d code(202) : eval()'d code on line 206 Warning: Invalid argument supplied for foreach() in /data/sites/web/somewebsite/www/wp-content/ plugins/akismet/favicon_316779.ico(105) : eval()'d code(165) : eval()'d code(202) : eval()'d code on line 207
  • 32. W P T H E M E L I S T R E S U LT Parse error: syntax error, unexpected '$z9973449' (T_VARIABLE) in /data/sites/web/somewebsite/ www/wp-includes/post-template.php on line 1 Warning: array_splice() expects parameter 1 to be array, string given in /data/sites/web/somewebsite/ www/wp-content/plugins/akismet/favicon_316779.ico(105) : eval()'d code(165) : eval()'d code(202) : eval()'d code on line 206 Warning: Invalid argument supplied for foreach() in /data/sites/web/somewebsite/www/wp-content/ plugins/akismet/favicon_316779.ico(105) : eval()'d code(165) : eval()'d code(202) : eval()'d code on line 207
  • 33. T Y P I C A L E R R O R S 
 A N D H O W T O F I X T H E M
  • 38. Warning: Cannot modify header information - headers already sent by (output started at /data/sites/ web/somewebsite/www/wp-settings.php:84) in /data/sites/web/somewebsite/www/wp-includes/ option.php on line 920
  • 39. Warning: Cannot modify header information - headers already sent by (output started at /data/sites/web/somewebsite/www/wp-settings.php:84) in /data/sites/web/ somewebsite/www/wp-includes/option.php on line 920
  • 40. Warning: Cannot modify header information - headers already sent by (output started at /data/sites/web/somewebsite/www/wp-settings.php:84) in /data/sites/web/ somewebsite/www/wp-includes/option.php on line 920 Fix: 
 Enabe output_buffering
  • 41. Q U E S T I O N S ?
  • 42. T H A N K Y O U ! 
 S L I D E S W I L L B E T W E E T E D O N 
 @ B R E C H RY C K A E R T 
 
 A N D P U B L I S H E D O N H T T P S : / / B R E C H T RY C K A E R T. C O M