Prestashop migration error

[albert9871]

Well, first of all, I'm migrating a Prestashop with version 1.7.8.7 to a VPS server. After transferring all the files and the database, there were no errors. I can see the homepage, but when I try to access any other page on the site, I get a 404 page not found error. Also, when I try to access the admin panel, it doesn't let me in. I've changed the URLs to point to my new domain, and after that, I was getting a 500 error. I've activated the debug mode, and this is what it's showing me: 

I forgot to mention that I downgraded the PHP version from the Plesk server from 8.0.28 to 7.4.33, and the errors I mentioned earlier are due to version 7.4.33. When trying to access a page or the admin panel, I get a Server Error 404 Page Not Found message. As I mentioned earlier, I changed the URLs to point to my new server, and I don't see where else I need to make changes.

(EDIT) Now this is the error what i get 

I hope you can help me. Thanks ! 

Edited April 26, 2023 by albert9871 (see edit history)

[WisQQ]

Try to disable friendlyurls, it will regenerate htacesss. Disable all 3rd party modules and try to enable them onebyone.
First error says that inside PosSaleProductsWidget.php you are trying to call undefinied variable.