Modules & Services does not work???

[No1guitarshop]

Hi
I purchased the advanced event bookingsystem and downloaded it to my machine.
In the prestashop backoffice I tried to upload the files but only got this response:

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.

Now everytime I try to go to Modules & Services I end up in the same message.

My website is www.no1guitar.se 
PrestaShop version: 1.7.2.2
Shop URL: http://no1guitar.se/
Current theme in use: classic