Error: 'UNITY_PASS_FORWARDBASE' : macro redefinition

I made a shader using Shader Forge in Unity 2017 that appears to have broken in Unity 2018.
The error doesn't stop it from compiling, but it is visibly incorrect.
There's also the possibility that this isn't causing the change I'm seeing.

The error:
'UNITY_PASS_FORWARDBASE' : macro redefinition d3d11

The line specified:
#define UNITY_PASS_FORWARDBASE


EDIT: It appears that the shader only visibly breaks when HDR is enabled. If I had to guess its a weird issue with this beta of 2018 so I'm gonna do more tests and see if it is. This thread can probably be closed

EDIT 2: Nope, it just breaks in HDR with any version. Yeah this thread can be closed

 

your not using SRP, Shadergraph or lightweight/HDRP? because then ofcourse itll break

if your not using those, then I would message the asset author

 

I got the same problem with an old Shader Sandwich shader.

@GameDevCouple_I: Your answer is pretty cryptic to me. I just updated my project to the latest Unity version and this error popped up. How can I avoid this stuff?