Internal Server Error -- Solved

Hello together,

I am having an issue with my installation of Opencart.
I am Getting an Internal Server Error (500) when I try to add an Order via Dashboard, the problem seem to be more general since when I performed a transaction and Pay via Paypal everything works but no order shows up.
POST https://stage.tassen24.ch/index.php?rou ... store_id=0 500 ()

There is another Call when I Pay via BankTransfer which also causes a 500
GET https://stage.tassen24.ch/index.php?rou ... er/confirm 500 ()

Another one is if a User Registres an account and submit it I land on a Blank page.

Otherwise, the shop seems to work fine.
Environment:
The Shop is running inside a container(Docker) with changing IP.
SSL Termination happens in NGINX and request are forwarded to an Apache Container with PHP 5.6
php:5.6.31-apache
https://hub.docker.com/_/php/

Any Help is welcome.

Kind regards
Gradlon

The topic is set to solved but the post itself does not indicate the solution. Is it really to understand that this enquiry has really been solved?