Cannot add product to cart prestashop 8.1.3

[jonyis82]

Hi, I did a production prestashop upgrade 1.6 -> 1.7 -> 8.1.3 on a local pc. After uploading back to the server I put the product in the basket but it remains empty. I don't know what to try next?

Second, I tried a clean installation of 8.1.3 on the production server. I then tried to upload the database from the updated version from the local pc and the adding stopped working. It says products added but it doesn't happen. it looks like a problem with the updated database from the previous version. when I reloaded the database from a clean installation, adding to the cart started working again.

upgrade on the production server from version 1.6.24. to a higher version failed even once and always ended with internal server 500 error

I tried to upload the local upgrade to the production server and adding the product stopped working anyway.

it worked on the local pc and it didn't work on the production one

Edited January 29 by jonyis82 (see edit history)