I'm not really sure, I have seen some users report this but most works fine. Can you update from GitHub? This is verified signed by me https://github.com/barrydeen/wisp/releases/tag/v0.16.3-beta

It is a scary error because it is meant to be. This is Zapstore protecting you from an update from another developer. It was a bug on our end but the defenses are there in place and working.