Shop unavailable after updating from 5.1 to 5.2.8

Hello

i need help asap, else im gonna just run buckups to 5.1.

 

EDIT:

Okay, so i managed to do all that. Did buckup and started once again with deactived plugins. So right now i have working 5.2.8 shop with compatible plugins on php7. 

I have only one problem, the Themes manager is not working, receiving an 500 - Internal Server Error when trying to access it.

 

So i updated from 5.1 to 5.2.8 yesterday and today wanted to switch php version from 5.6 to 7.0. due to the ioncube_loader error.

I found article about it. http://community.shopware.com/Update-auf-php7_detail_1927.html

So as said, i opened plugin manager and started downloading the plugins first. After updating couple plugins the backend became unavailable.

The latest plugin was cookie agreement i think.

Strangely the fronted header is loading (including background color, tobbar, searchbar, logo, language and service links)

 

Thanks in advance

Regards

Okay, so i managed to do all that. Did buckup and started once again with deactived plugins. So right now i have working 5.2.8 shop with compatible plugins on php7. 

I have only one problem, the Themes manager is not working, receiving an 500 - Internal Server Error when trying to access it.

Did you check the website’s error log?

Timme Hosting - schnelles nginx-Hosting

www.timmehosting.de

@TimmeHosting‍ Yes, there seems to be no errors, all good (exept i am looking at wrong logs, var/logs )

Still need some help here.

bump