Why my Shader Graph always purple? [SOLVED]

I tried 2018 version since betas. Then there was such a problem. Now the same problem continues. My version is 2018.1.1f1.

Also I could not use Lightweight RP in beta versions. It was constantly giving “no Shader files”. Now there are no mistakes, but Lightweight RP files are always purple.

2018.1.2f1
How to make Shader Graph ready to use :

  • Window > Package Manager > All >SRPCore (Install)

  • to avoid some errors also install Post-processing

  • Window > Package Manager > All > Lightweight Render Pipeline (Install)

  • create it’s asset in project Create > Rendering > LightweightAsset

  • Assign asset in Edit> Project Settings > GraphicsSettings > Scriptable Render PipelineAsset

  • Window > Package Manager > All > Shader Graph(Install)

I’m having the same problem using 2018.1.2f1