Okay so I've been searching the forums for two hours and a lot of people seem to have the same issue - shift+F12 don't open the menu, and people tell them to use a different keybind. I figured out how to do that for ENB but not for ReShade. The config seems to be... rather empty.
Not sure what I need to show you, but here's all the files (not folders) in my Skyrim folder:
Here's what's in the ReShader Config: GENERAL
EffectSearchPaths=\Programs\Steam\steamapps\common\Skyrim Special Edition\reshade-shaders\Shaders
TextureSearchPaths=\Programs\Steam\steamapps\common\Skyrim Special Edition\reshade-shaders\Textures
Here's the settings I copied from the ENB config (changed the keybind code thing with the help of a website so it wouldn't conflict, still doesn't work): INPUT
I have this same problem and it is really annoying. I have tried disabling the steam overlay and the geforce experience overlay to no avail. Maybe enb overlay is conflicting? This wouldn't make a whole lot of sense as there are tons of enb's used with reshade and made specifically for reshade. Would really like to see a fix for this.