It’s impossible to solve errors without at least a stacktrace, but DEX errors are usually as a result of method count limits. If you target API 20 or less, you need to follow a few steps documented on the Google website about this known limitation. If you target API 21 or above, I believe all this is done automatically.
Regarding compiling native jars, I’m completely in the dark without a stacktrace.
I’ve written an Android game. It is tedious at times but it’s more an Android thing than the engine itself. Perseverance is the order of the day