Cause
If when trying to access the Feed Sources page (or the Feed to Post tab in the Settings) you get an HTTP ERROR 500 on a blank page, these symptoms suggest that a fatal PHP error is occurring on that page, but you cannot see it due to your server’s setup.
Solution
Please try the following:
- Enable WP_DEBUG and WP_DEBUG_DISPLAY.
- If you don’t get desired effect (fatal error displayed), examine your server setup, and look for the display_errors directive.
After this, the page that gives the Server Error 500 should instead display a PHP error. Please send the text of that error to us via our premium support channel and we’ll help you look into it.