phpBB start giving me 500 Internal Server error

I start getting the error when I try post/edit any post into my forum when I
the page take some time to post and the page show 500 error message

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

I try check with the dreamhost support and they told to increase the time limit for execution
I try adding the PHPRC but nothing changeā€¦

So i try add the php.ini
but once i add that file, I got the MYSQL error