cannot roll back with 1 click upgrade

[chaosicq]

Upgraded from version 1.61.18 to 1.7.6.3 all module updates failed, the shop has a 505 error when taking out of maintenance mode so thought i would roll back, however in the drop down the file to roll back is there but the roll back button does not light up to work, the box above which shows :

 

PrestaShop Original version:

Differences between versions:

   is still trying to load i think that is why it is not allowing me do it  1 click update is the latest version.

alternatively can i manually roll it back? from the file.