Hi, Catharine, Happy New Year!
When you get this in Design Checker, it usually means "This won't publish as a browser form". :)
Here is what I usually do. I make a copy of the form to tear down. I then create a new blank view, and remove all other views one at a time, running design checker after each change. This lets me narrow the issue - if it is something in the view, the design checker will return its usual list of warnings instead of "could not verify".
If, with all views except a new blank view removed, I still get that message from design checker, I start removing rules, usually in batches, keeping track of what I've removed, and running design checker. The last time I did this, the issue was a rule condition where a group had been selected with the condition "is blank" - IPFS did NOT like that.
If the issue is a view, I usually create a new copy of the form and remove parts of the view, running design checker as I go - again to narrow the issue down.
Hope that helps -