Apple AppStore reports bug

I have been successful in adding my e-library to the GooglePlay store by the Apple App store sent me the following message. Any ideas on how to resolve this?

We discovered one or more bugs in your app when reviewed on iPad running iOS 13.3 on Wi-Fi.

Specifically, the app continued to quit unexpectedly when we attempted to view the books found in the library, preventing further review.

Have you tried the app running on an iPad with iOS 13.3 on Wi-Fi?

Can you send me a copy of your project through private message or email (chris_hubbard at sil dot org)? I can try to take a look.

Chris

Chris, thanks so much for your response. I have submitted this twice and both time they responded with the message:

“We discovered one or more bugs in your app when reviewed on iPad running iOS 13.3 on WiFi. Specifically, the app continued to quit unexpectedly when we attempted to view the books found in the library, preventing further review.”

After receiving the first message I noticed that in the book menu, I has targeted the book but not the chapter. I corrected this so that all books are targeted to go to chapter 1. This seemed to resolve the issue on the iOS App in Simulator. I cannot replicate the problem now using the simulator but for some reason, after making this correction the returned with the same message.

Problem seems to have been in selecting target in RAB. With Android selecting a book target for the Contents Menu did not require targeting a chapter -it seemed to default to the first chapter if a chapter was not chosen. iPhone required that I not only select a book but also the chapter as a target. It would hang up if no chapter was chosen.