Got the 204401 Errorcode today.. i didnt do anything with my dropbox password.. now it dosent sync anymore.
I use enpass on Windows
and 3 Samsung phones and 1 Tablet
and this advice didnt help at all
Disconnect Sync from all devices.
Open Dropbox on any browser->Go to App -> Enpass folder -> Vault.enpassdbsync -> Rename it as Old vault.enpassdbsync.
Now open Enpass and enable Sync on all devices.