@kurulumu-Net hmm. That certainly would indicate that 16.x is supported. I was told by @baris some time ago that this wasn't in fact supported, but that could have changed since our last discussion - or, the documentation is incorrect.
@oplik0 that's entirely incorrect. git fetch does literally nothing to local files, and even if it did, ./nodebb upgrade only affects the database and files that aren't handled by git.
Oh, possible. It probably fixed things for me because my problems were mostly due to me messing with NodeBB files. It seemed to reset the upgrade then, but that probably was because it didn't get to actually changing anything while I broke it.