This is the first we’ve heard of an actual crash, but this is probably related to the problem described in Coastal Explorer on iPad Flashes and Loops Endlessly. Unfortunately that is caused by a bug in iOS/iPadOS version 15 and we have not yet found a way to work around the problem, though we are still working on it. Apple has been made aware of the problem which is affecting many apps, not just Coastal Explorer. Hopefully they will have a fix in the upcoming 15.2 release.