Invalid Answer for a Drag and Drop Interaction?

Hi folks,

I'm looking for some help with an interaction. (My apologies if this has been asked and answered before. I could not find a prior post on it.)

I am building a drag and drop interaction where there are six drag objects and three drop targets. The learner will hover over each drag object to see what it is about, and then drag and drop on the target. When I try this out in Preview of the slide or the scene, I get an "Invalid Answer: You must complete the question before submitting" error message. I've worked on troubleshooting this, but I can't figure it out, yet. Suggestions?

Starting/Base Layer Screen

Almost-Completed Interaction with Error Message

 Thanks in advance!

--Steve