I, too, received this error on my Mac (Big Sur 11.2; Enpass 6.5.1). I signed out from syncing to Dropbox, but when trying to reconnect with Dropbox Enpass gives me the error message, "Could not verify your credentials. Please log in again to sync your data."
Dropbox sync broken for Mac and iOS. Error 204035
in iOS
Posted
Exactly the same problem here