Most will recommend always using the off-line installer to upgrade. It seems to be more reliable. There have been many posts of users who updated via the "update button" inside the app, which were fixed by running the off-line installer over top.
Glad your issue is fixed!
KidJoe
Over the two years I've been using StreamFab, the built-in updater has only caused me problem a couple of times--occasionally MAJOR problems. But with multiple DRM issues in 2024, I've come to agree with you. And I save each of the StreamFab version downloaders in a special folder to make it easy to revert to an earlier version.
Wishing that the auto-updater would work consistently doesn't seem to be a reliable strategy.