Android Crash: JNI Bridge

I am getting an Android crash:

Code (CSharp):

1. jni::Java_bitter_jnibridge_JNIBridge_00024InterfaceProxy_delete(_JNIEnv*, _jobject*, long long)

It happens on restarting Unity after a couple of times, note this is having UnityPlayer embedded within an Activity, and opening and closing that multiple times. Does anyone know what this means?

 

That line appears to be in here: https://github.com/bitter/android-jni-bridge/blob/master/Proxy.cpp so it is causing an error when a pointer is being deleted. I assume I haven't unloaded it Unity correctly and that's the problem? Any help on how to properly unload Unity?? (I am currently using Application.Unload())