1click update Unable to check files for the installed version of PrestaShop 1-click upgrade

[visco82]

Good evening,
I would need advice.
I've been banging my head for a few hours but I can't find a solution.
I would like to upgrade from version 1.7.7.7 to 1.7.8.8 via 1-click upgrade module.
All requests Checkup list before upgrade are correct.
By selecting minor release, the module does not search for the new version available (photo attached)

 

Even selecting the expert mode and local directory, inserting all the extracted files in the latest folder as requested, it gives me the following error when comparing the files:
Unable to check files for the installed version of PrestaShop.

Differences between versions:
Unable to generate diff file list between 1.7.7.7 and 1.7.8.8.

(photo attached)

 

If I start the update in this mode obviously it stops immediately telling me that I already have the latest version.
(photo attached)

I checked the file and folder permissions of the module as suggested in other posts, uninstalled, reinstalled, cleared the cache.
I can't understand the reason for this error, does anyone know how to help me?
Thank you in advance