You may have a bad plugin causing the 'white screen of death' when you try to get into the admin area.
Check the error.log file in the wp-admin
folder. That should give you an idea of where the problem is.
You could also manually disable a recently-installed plugin by renaming that plugin's main folder in wp-admin/plugins
. But looking at the error.log file should be your first step.
Added
Add this code to your theme's functions.php file at the very top (after the <?php
). It should cause error messages to be logged and shown on screen. Note that it may cause some errors to display on the live site depending on the type of error. But it might give you some clues:
// simple error trapping on screen
// Report simple running errors
error_reporting(E_ERROR | E_WARNING | E_PARSE);
// full errors
// error_reporting(E_ALL);
ini_set('log_errors','1');
ini_set('display_errors','1');
Hope this helps.