Can't apply upgrade because the following files were modified: modules/base/general/classes/BxBaseModGeneralModule.php
I got a message similar to that:
"Can't apply upgrade because the following files were modified: template/images/cover-homepage.png, template/images/cover.jpg"
If it's ok to overwrite modified files, then you can enable the following option:
Studio > Settings > System > SITE SETTINGS > Force site and module auto-update, even if some files were modified
Then try to upgrade again
I keep forgetting about that switch Alex, thank you!