Google ripped my Chrome extension off the app store about a month ago.
I got a similar cryptic message, and then I scrambled to fix it, like you're doing now. Somehow my extension reappeared the next day.
Email me pat [at] trypigeon [dot] co and I can send you some of the things I did that maybe have helped.
Tweeting my support as well: https://twitter.com/thepatwalls/status/1260638967793242113