Repro steps:
1) Open the project
2) Select VisualReceiver.shader and make sure Skip unused shader_features is deselected
3) Click Compile and show button of the shader in the Inspector
4) Notice the errors in the console:

===
Shader compiler: internal error compiling shader snippet type=0 platform=15: Protocol error - failed to read correct magic number
Shader compiler: internal error compiling shader snippet type=0 platform=15: Protocol error - failed to read correct magic number
UnityEditor.DockArea:OnGUI()
Shader error in 'FastShadowReceiver/Projector/Visualize Receiver': Internal error communicating with the shader compiler process
===

5) If you close the Unity it will become non responsive

Workaround: do not skip unused shader_features

Reproduced in: 5.4.0b4;5.3.2p1;5.2.3p2