500 internal error with updated MySQL

[bou24]

I'm getting the Internal 500 error on 3 different installs when server was upgraded to Mysql database version 5.5.35+wheezy1, running Apacke/2.2.9 (Debian) PHP/5.3.3.
However. Database client version: libmysql - 5.0.51a <--- could that be the cause?

When trying to access wp-admin -> permalinks i get internal 500 error. Neither server or wordpress logs says anything. .htaccess has been tested out a million times.

Clean install of earlier working 3.8.1 & 3.8.2 is now not anymore working since database update from the hosting company.

I've also tried a new browser and resetting my own browser settings just to rule those out.

[ocean90]

Please try the support forums for troubleshooting: ​​​https://wordpress.org/support/

[Denis-de-Bernardy]

Itching to re-open this, because I'm pretty certain WP could do something about it.

Related: #27749

Here's a SO reference with a proper solution (aka use mysqlnd or recompile PHP):

​http://stackoverflow.com/questions/10759334/headers-and-client-library-minor-version-mismatch

A potential WP-level fix is in those answers:

$err_level = error_reporting(0);  
$conn = mysql_connect('params');  
error_reporting($err_level);