Now this one is weird. Tried it with Beta 2 RC 4 in C4D R20, latest, running under Windows 10 (latest, too).
- Create a new Corona material
- Create a Layer Shader in Diffuse
- In the Layer Shader, create a noise shader
- Doble click the word "noise" to rename it
- Do not rename it but click below the word in an empty area of the shader
C4D minimizes.