Well Darn, so I uninstalled it, and then reinstalled in C:\MO, as per your advice. It installed 1st time, which was nice, but now the program won't open. Just says "FAILED TO CREATE DEFAULT", same as this guy on github. I tried copying across an installation from my old PC, and it still creates the same error. So now im superstuck. Fix : Short answer: Uninstalll MO and all its files and MAKE SURE YOU DELETE C:\Users\USERNAME\AppData\Local\ModOrganizer folder! A re-install will hopefully then work. :) Long answer: Hi, I just had this issue, and 'fixed' it. I did a TONNE of stuff prior, that may have helped(unlikely mind), but I can only tell you my final few steps, that allowed me to have MO working again. First I completely uninstalled it, and all my path location for mods, cache, profiles etc. Turned out the very original ModOrganizer folder had remained in C:\Users\USERNAME\AppData\Local\, and hadn't been removed. Once I deleted that folder, I restarted my PC (and did a registry clean/fix in CCleaner, doubt that matters tho). After the restart, I ran the installer again, and it worked :) Hope this helps, please comment if it so other sufferers know to try it. :)