Error: 'failed to open source file: 'CoreRP/ShaderLibrary/Common.hlsl' what to do?

Error msg:

Shader error in 'HDRenderPipeline/Lit': failed to open source file: 'CoreRP/ShaderLibrary/Common.hlsl' at line 282 (on d3d11)

Unity Version : 2019.3.0a6 (HDRP/LRP)

I've been playing around with the HDRP and the LRP versions of unity for a couple days and everything was fine untill i got this error. Last week i have used the HDRP version of unity without issues. But for some reason this error message started popping up. i work in HDRP/LRP is because of the shaders, so its a real pain. I have reinstalled unity and the unity hub atleast 3-4 times to no avail. I have googled around and i could only find old posts from 2018 and no solutions.. I'm no coder/developer, and i have little to none coding knowledge. Im really running out of answers here, so i could really use some help.

Thanks in advance,

Victor