I found out what the potential issue is - at least what my issue was. Everyone kept saying that the symbolic error was due to permissions, but it wasn't. Firstly, try running command prompt. If it loads for a split second then cancels, then that's your issue. Apparently Windows 10 likes to screw up command prompts at times whenever you do a PC update. Mine was refusing to load and FMM needs command prompt to be working to be able to create ModData and the subsequent folders and files.
If that's the same issue for you, just google a fix. The only way I could get it to work was creating a new Admin User profile and then running FMM. Now it works like a dream.
Posting this here as I've had the issue for 4 or so months, and everyone on the Frostyeditor Discord has been replying condescendingly with 'ITS A PERMISSION ISSUE FOKKIN NOOB LOL CHECK THE SOLUTIONS TAB'. Yeah, nah, definitely wasn't a permissions issue.
Edited by imogeneA91, 30 October 2018 - 12:33 AM.