Redshift noise error with Isolate selected

I have 2 shader connected to Material blender & use maxon noise -> mask -> okie

But when i create displacement blender -> connect 2 displacement from 2 shader -> okie

but when i use maxon noise & red channel to displace weight 0 channel and press isolate selected mode to change some value in Renderview -> my error, pls see my attached file. :-s. I dont understand

https://drive.google.com/file/d/1PHWVeerNdySyJmuRmoWbABzjfj90rduq/view?usp=sharing