Recently I was trying the new Unity Input System package on a cross platform project.
Everything was going well until I switched to the tvOS Build Setting. Then, the project would not run in the editor nor would it build.
It appears that the Input System package has a dependency on the VR package but there is no VR support for tvOS. So, the project will not build.
The solution was to disable the built in VR package in the Package Manager:
Once you do this, then you will find joy and your tvOS build will succeed.
Also, I raised the issue on Github and the Unity folks moved it here for tracking:
Note: The original blog post that helped me solve the problem can be found here: