Using Vuforia 8.3.8/9 in Unity 2019.2.4f1, I am unable to edit the Default Mid Air Indicator Prefab (materials and size). When I attempt to open the prefab, Unity crashes. I was able to adjust this prefab in earlier versions of Unity/Vuforia. Given issues with Android 64 bit build, I must use the latest version of Unity. Can anyone help with this issue? Steps to recreate:
1. Create new project in Unity 2019.2.4f1;
2. Select project settings/XR Settings/Vuforia Augmented Reality Supported
3. Select packages > Vuforia Engine AR > Vurforia > Prefabs > DefaultMidAirIndicator
4. In Inspector, select "open prefab"
5. Error message, "Argument Exception: Saving Prefab to immutable folder is not allowed:"
6. Force Quit to exit unity