Ok so I reinstalled SMIM. If I check the core patch.esp, using the override folder and then hovering over the .esp in the plugins list, it still says I have all the necessary masters enabled. If I know try to install the Patch via the mod manager (STEP Compilation Installer - Normal Res - 2292l-11-2-2-9-2l.7z) it asks me if I have installed SMIM and Realistic Ragdolls which I have done. Then it tells me I can't install the extended patch which I expected. The ineligibility box is ticked and I click next. Now it tells me I can't install the Core patch. I'm not really sure what I am missing as I also made sure to check all the plugins listed in the op are indeed enabled. Regarding the internal/external FOMOD installer: I'm pretty sure I haven't turned off the internal installer. I have been installing mods with MO by downloading the archive using the download with NMM link. They end up being in the file ~Steam\steamapps\common\Skyrim\Mod Organizer\downloads . When I now want to install it, I clicked on the install button and choose the archive out of that folder. So am I still using the internal installer this way?