Could anyone tell me how to solve my problem?
I have "500 sever error" when I wanted to login Backoffice after I changed PHP5.2 to PHP5.5 at 1und1.de (Germany) control-center because I want to terminate PHP5.2 it needs to have extened support with extra fee. I have tried both 5.4 and 5.6 as well, the results were same.
My e-commerce site is working well but I can't login to Back office (admin) except PHP5.2 set up.
Prestashop version 1.6.0.11
I believe I didn't have any problem when I use version 1.6.0.9.
When changed again to PHP5.2, everything work fine...
Please suggest;
1. How to find problems.
2. How to solve these problems.
Thank you in advance.