We use the VaultWarden alternative BitWarden server. This morning I woke up to my dad not being able to log into his BitWarden desktop client. He'd enter his master password, and instead of unlocking his vault, it'd immediately give a rather unhelpful error indicating that an unexpected error has occurred. During troubleshooting, I deliberately entered an incorrect master password with the same result, proving that it wasn't getting far enough to even try to unlock the vault. Turns out I hadn't updated the VaultWarden server in a few months, and updating the server fixed it. Apparently the version of the client running on his system was too new for the server. I know BitWarden is a unique situation where they're probably only putting up with VaultWarden because they have no choice. But I'd think it should be standard practice any time you have a client/server relationship that if one is too new or too old to be supported by the other, the user should get a helpful error message explaining this.