Hey Greg, thank you for your answer. I installed my legal Skyrim properly on C:\Program Files\Steam\steamapps\common\Skyrim\ on 11.11.2011 (indeed right after release cause huge fanboy) and everything about it appears to be correct. I also ran Skyrim from desktop (with and without admin settings) but FNIS still announces this error *Error(5)* After about two hours of copying my whole MO directory from C:\Program Files\Mod Organizer\mods\ into my Skyrim dircetory, everything with FNIS seems to work fine again. I guess my problem is solved. But I still wonder, why the f*ck does this make a difference? And, to be honest, I might have screwed up my MO myself, cause I decided it would be a good idea to update all mods and plugins. Everything with MO not being in Skyrim directory worked just fine before that. I used an older version of MO, SKSE and FNIS till then. Errors occured after updating all theses. So in conclusion, better put ya MO stuff into Skyrim directory! I just hesitated to copy all dem 90 mods into Skyrim, because my PC performance made a huge thing outa it. It was pretty easy. Just install MO (via unzip) into your Skyrim (NOT data) directory and copy your old directories into it, without overwriting any exes or dlls. Then you might need to reorganize or reinstall some mods/plugins within MO again, but that should be it. In the end, I still think the problem lies within the MO/FNIS relationship, because I made sure and rechecked if everything was properly installed (according to STEP guide) I still thank everyone for this constructive forum I hade the pleasure to spent some time with. I hope my contribution might help others and keep up the good work. (=