Website multi-lingual pages unavailable in Plesk: 500 Internal server error

Applicable to:

• Plesk for Linux

Symptoms

• Website multilingual pages like example.com/nov or example/com/sv are showing the error:

  CONFIG_TEXT: Internal Server Error
  The server encountered an internal error or misconfiguration and was unable to complete your request. Please contact the server administrator at [no address given] to inform them of the time this error occurred, and the actions you performed just before this error. More information about this error may be available in the server error log.
  Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request. Apache Server at www.example.com Port 443

• The following can be found in /var/www/vhosts/system/example.com/logs/error_log:

  CONFIG_TEXT: AH00124: Request exceeded the limit of 10 internal redirects due to probable configuration error. Use 'LimitInternalRecursion' to increase the limit if necessary. Use 'LogLevel debug' to get a backtrace.

• The website is built on WordPress
• The main part of the website is working perfectly and not showing any errors on other pages

Cause

Plugin conflict between WPML (WordPress Multilingual Plugin) and other plugins/theme.

Resolution

1. Log in to Plesk
2. Disable plugins one by one to find the faulty one in Domains > example.com > WordPress > Plugins > Deactivate button
3. After a faulty plugin is found either remove it or contact plugin developer for further assistance