Error upgrading 1.7.8.10 to 8.1.3

[Avgvstvs]

Hello,

I have a issue upgrading my Prestashop (subdomain installation) from version 1.7.8.10 to 8.1.3. 

My current PHP version is 7.4.33

Using local archive and 372-Click Upgrade module I've tried to upgrade PS version but received the following error:
 

Quote

[INTERNAL] /home/aewsport/presta.nenovsport.com/config/bootstrap.php line 87 - require_once(): Failed opening required '/home/aewsport/presta.nenovsport.com/var/cache/prod/appParameters.php' (include_path='/home/aewsport/presta.nenovsport.com/vendor/pear/pear_exception:/home/aewsport/presta.nenovsport.com/vendor/pear/console_getopt:/home/aewsport/presta.nenovsport.com/vendor/pear/pear-core-minimal/src:/home/aewsport/presta.nenovsport.com/vendor/pear/archive_tar:.:/opt/cpanel/ea-php74/root/usr/share/pear')

After the upgrade, the frontend and backend have ERROR 500. 

So I've tried a few things but with no success: 

Disable cache, clear cache, delete var/cache/ directories, hard reset browser cache, change all file and folders in var/cache to 777... even tried to upgrade to older version 1.7.8.11, but no, the issue still exists. After every step mentioned above, I made a new upgrade, and had to rollback to 1.7.8.10 stable backup file.

Any idea how to solve this?

 

Thanks in advance!

Edited February 2 by Avgvstvs (see edit history)

[Avgvstvs]

SOLVED: In Advanced Parameters - Performance - Turn on Debug mode - Template compilation: Force compilation - Turn off Cache, set it to No. Rename the cache folder in var to cache_old.