It is suspected that a PHP Exception (Fatal Error) occurs. However, no error message is visible in the browser. In the usual log files of the webserver, no details or stack traces are shown.
The logging has been disabled in the PHP configuration, or the logs have been redirected to another location.
Call phpInfo() and look into the section "Core". The following entries are relevant:
- The entry "error_log" shows the path to the log. If it says "no value", the server's default path is used. For Apache: /var/log/apache2
- The entry "log_errors" must be set to "On". If it says "Off", no errors will be logged.
- The entry "error_reporting" represents the log level, in other words the error severity to be logged. By default, this should be set to "22527".
The configuration can be set in the php.ini. Further details about Error Handling can be found here.
You can also enable the option display_errors to see error details in the browser. This can be a security risk and should only be done on non-public development systems! As soon as the problem has been resolved, this option should be disabled.