That's interesting. I did not realize that the WRP required Archive Invalidation. I've used it before without messing with Archive Invalidation and never had problems. I honestly don't recall ever looking at the install instructions. I might have looked at them at one point, but forgot about the AI requirment. I'm using NMM because it's easier for me to deal with, as everything is in one window, and it's the first MM I started with when I started modding Skyrim. With FOMM, I'd have to have two separate windows open, one to display my load order, the other to allow me to add and remove mods. If I went to launch the game while the second window was open, I'd get a message saying that I needed to close the window before launching the game. I am currently using FOMM for one mod, and one mod alone, and that's Darnified UI for Fallout 3. For some odd reason, DUI would not install under NMM. And a couple of people on the DUI thread over on the Bethesda forums suggested using FOMM for that, and I decided it was a good idea. Right now I'm using mods that do nothing more than add weapons and change textures, so I don't need the MM to launch the game, I can still launch the game from Steam. The only times I need the MM to launch the game, is when I'm using mods that require a Script Extender.