Login to admin failed

Hello, i am new to OXID, my former collegue was managing our shop but he has left us … ;( So please be patient with me…

Our Store: http://shop.sealko.de (OXID eShop 4.8.3 )

Since two days, the Login for the Admin/Backend doesnt work anymore!

>> If I try to login, the result is a empty “white page” and the URL is:

(Thats not the original link)

>> The same user can still login to the FRONTEND, so Username and Password is correct.

Could it happen, because our provider has changed the PHP Version from
PHP 5.3.27 to PHP 5.3.29 ??

Thats for now the only change, that happened during the last two days on our server, which I could find out.

Please help :slight_smile: