[UE4.7.0 Bug] Deploying to Nexus 9: ERROR: Unknown NDK architecture 'arm64-v8a'

Sorry, haven’t tried a destructible mesh (not in my current project’s scope)

Sounds like you might need to post a LogCat of your Android app and hopefully others may be able to help.

LogCats can be obtained with tools like Android Studio.

Best of luck.