make sure you don't have reshade installed into the games folder.

1.make a shortcut for the boiii.exe and right click the .exe go into properties(if you're on windows 11 show more options and then properties) and in the "target" section under the target location where you can actually type leave everything as is but add a space to the end of the text and add -launch this will skip loading the client and load straight into the game(I don't think you actually have to do this part but it saves a lot of time and effort by not having to click play)

2.run the reshade.exe and click "browse" and go into the black ops 3 folder and select the base games "black ops 3.exe" and install it normally

3.Run the boiii.exe and proceed as normal

Might I suggest downloading these files from the MRTLEXIFY video I will link below as these actually make the game look amazing but do keep in mind if you plan on using these you must set your Anti-Aliasing to SMAA T2x in advanced settings or you will just have a black screen when loading into zombies and the background of the main menu will be black also.

https://youtu.be/uIFoaUE3uvY(sorry if you don't want me posting links to stuff that link to things like github I tried this myself and it's actually really good)

Have fun KING!!!!!!!!!