July 19, 2015
Fix the 500 error on WordPress
WHAT IS THIS ERROR?
500 Internal Server Error
The server encountered an unexpected condition. It is a multipurpose error that displays when the server cannot gather any specific information about the problem. This error often occurs when the server cannot fulfill an application request because of a misconfigured application.
To resolve this issue, contact your system administrator. [Source]
If you see a 500 error, check the path to your WordPress folder in the .htaccess file. Again, you might need to look at your hosting folder setup to get the full path. [Source]
1) Disable plugins and reinstall one by one, to check if any conflict.
This is a terrible recomendation. I've not tried it.
2) File permissions are incorrectly set for the WordPress installation files.
Once higher version of php has been activated, clear browser cache.
3) Pass the default character set parameter
Improving Performance by Passing the Character Set ^
Prevent certain 500 error displays by passing the default character set parameter before you get there. Note: replace the “utf-8” below with the charset that your site is using (add to .htacess)
# pass the default character set
This didn't work, so I've removed it.
4) DON'T DO THIS!! WHEN I DID IT, PHP STOPPED WORKING AND INDEX.PHP BECAME VISIBLE AS AN ORDINARY FILE
To the .htaccess file add:
AddType x-mapp-php5 .php
AddHandler x-mapp-php5 .php