Anyone else seeing - "Object reference not set to an instanceof an object"?

[WillowMobileSys]

UPDATE:  This error is also impacting Bots.  My client and I both have different apps where Bots are failing for the same reason described here.  This is now a critical issue that needs addressed immediately!

I am getting this error, out of nowhere, in an app I am editing AND it was reported to me by a client in another app I do not have access to.  Meaning its affecting multiple apps and likley an AppSheet Side problem.

Regardless,  App Creators should never see these type of error messages.  They are useless to us.