"500 Internal Server Error" after upgrade to PS 1.7.6.0

[taitaipiepies]

I just upgraded a complete clean (nothing installed, nothing changed after a standard 1.7.5.2 installation) via One-Click-Upgrade to 1.7.6.0 and two topics in the Administration bring up the following error:

Oops! An Error Occurred
The server returned a "500 Internal Server Error".
Something is broken. Please let us know what you were doing when this error occurred. We will fix it as soon as possible. Sorry for any inconvenience caused.

This happens when I choose in the BackOffice     ORDERS -> ORDERS      and      ORDERS -> SHOPPING CARTS

 

I cleared the cache, but no change, so I am a bit lost as there is actually no further error message....

 

Any help would be appreciated.

 

Thank you, Heiko

 

Here the server information:

Server information
Server information Linux #1 SMP Mon Dec 17 11:06:40 EST 2018 x86_64

Server software version: LiteSpeed

PHP version: 7.2.19

Memory limit: 756M

Max execution time: 600

Upload Max File size: 128M


Database information
MySQL version: 10.2.25-MariaDB

MySQL engine: InnoDB

MySQL driver: DbPDO

Store information

PrestaShop version: 1.7.6.0

Shop URL: http://www.koolquip.com/

Shop path: /home/koolquip/public_html

Current theme in use: leo_icook

Your information
Your web browser: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.103 Safari/537.36 OPR/60.0.3255.170

Check your configuration
Required parameters: OK

Optional parameters: OK