@NarnM If the game is reading the Sims 4 folder on D, as you've listed, then you probably used a symbolic link or redirected Documents to D without using a subfolder. Either way, the Sims 4 is looking for all your user content on D, not only the saves. So try putting your mods in D:\Electronic Arts\The Sims 4\Mods.
Edit: I just saw your new thread and merged it with your existing one. Please list the default location of Documents on your computer. Open a File Explorer window, right-click on Documents, select Properties > Location, and list the file path you see there.
I don't know where you read that the Mods folder only works on C. That's not technically correct: the Mods folder only works if it's inside the Sims 4 folder the game is reading, and that folder is on C by default. For you however, the folder is clearly on D.
