Same issue here.
In case you really removed all sweetfx files from the previous version (like I did) you can try this,
From the author at AC forums:
One thing you can try is to install it from original setup. Just download it from https://reshade.me/ .
After install copy the gbw-reshade.ini to Main folder and set this as preset file in dxgi.ini.
Tell me if this works. I removed the absolute paths in the dxgi.ini to get relative links to the files. Maybe this is the problem.
Source
Sadly didn't help me.