When your Veracrypt mount fails could be a bad file
OK, this is a strange problem, but I'll document it for myself. I use Veracrypt to store my ssh keys and other things. They are actually protected by passwords, but as a safeguard, I also store them in a secure Veracrypt mount that is in turn in a Google Drive so I can share it with all my machines (clever huh!). And I don't have to worry about updates.
Today, I suddenly found that when trying to mount the Veracrypt volume, I was getting an MSDOS.mount error that was msdos_mount unsupported sector size (0). What the heck is going on.
Well to debug this, you can go to the Disk Utility and try to mount the volume. It comes up blank. Then I saw that the volume on Google Drive had a conflicted entry. This can happen if there is an update
Turns out that somehow Google Drive corrupted the veracrypt file or one of the machines I have done. The solution fortunately is that Google Drive has a history function so I could go to an old copy, pin that and download it and replace the bad file. I also created my own backup just in case the history fails and will work. Now you know :-).