I’ve been having this issue for awhile- even though the masterkey file is in there, when I try to open the vault on my iPhone it just says “opening vault” and spins in a circle forever until my phone locks, or if I keep it open, it’ll do it for 5 minutes or until I give up… The google and Dropbox vaults don’t have this issue.
Two causes I’ve thought of: the OneDrive vault is much bigger, a few gigs as opposed to less than one for the others. Also, I don’t see the “m” folder in my OneDrive folder because I accidentally must have moved things around during a deduplication process, though I’m 99% sure it was happening before that happened and don’t think it is related. Anyone heard of this?