Hello,
I upgraded a shop running 1.6.1 to version 1.7 on a Linux server running PHP 7.2
The overall impression is that the upgrade is seriously buggy.
I refer to a manual upgrade done by the onine docs, which is the only available option.
After the upgrade I was able to enter the backoffice, but the frontend Shop was totally KO due several errors I found in the server's log.
I discovered with some trial and error that most problems are due to old modules being incompatible. I was very surprised of this because before upgrading I was using the default-bootstrap theme and set the "disable non-native modules" option. I even checked that all active modules were by "Prestashop".
Right after the upgrade I want to the modules upgrade section, and it turns out that no module can successfully upgraded. Every module upgrade fails and I have found you can improve this by applying this procedure:
1) trying a module update on one module, chosen between the proposed modules to be upgraded. The upgrade fails with the red notification top right of the screen.
2) Check the server's error.log, it turns out that some error has popped up in some old module (totally unrelated with the one I tried to update). Most of the errors are of this type:
QuotePHP Warning: Declaration of BWDisplay::setTemplate($template) should be compatible with FrontControllerCore::setTemplate($template, $params = Array, $locale = NULL) in /var/www/html/modules/name-your-module-here/backward_compatibility/Display.php
when name-your-module-here is always a different module.
3) I uninstall+remove or physically remove the module folder, then restart from step 1, only to discover that a new error of the same type (this BWDisplay::setTemplate - backward_compatibility problem always there) popping up in a different module.
By applying the above procedure I eventually was able to make the frontend shop to run (I did not place an order yet), but I still have several modules needing update and the thing goes on and on.
I would really appreciate any hint for understanding what's wrong on the above installation.
Perhaps during update any non-standard module shoud be disabled in order to minimize these issues.