Could you post some more details? What version of Reshade/SweetFX are you using and what DirectX version are you using?
If it worked before but doesn't work now it's possible the game or a piece of DLC got updated and messed Reshade up. There is nothing you can do about that.
SweetFX_settings.txt (UTF-8 without BOM) Important!!!
Note: Use the program Notepad++
Required Files:
- Direct3D 10+
SweetFX (Folder)
dxgi.dll
ReShade.fx
Sweet.fx