Been using Enpass macOS on my work laptop with ZScaler for several years.
Today, I go to open my vault and am met with this same error. Tried on and off corporate VPN, same result.
If it weren't for the fact that I found the vault.enpassdbsync file on my macOS filesystem, exported it, and opened it on another machine, I would be locked out of all my critical work passwords that I rely on daily with no recourse.
Thank god I recovered my vault on another machine. Now I can export the passwords and sprint away from Enpass permanently, given several other users have reported being locked out in recent days/weeks with no apparent solution in sight.
This is the moment you learn that you would've been better off using sticky notes than trusting Enpass, regardless of how well it worked up until it didn't.