I'm having the exact same issue. Just started 2 days ago. I haven't changed / moved any files or even exported any presets for a few weeks now, yet this just happened. Everything was working perfectly before hand.
-EDIT- I FIXED IT
Really simple too. Just make sure you untick the box that saves your username on the login screen,
and export the preset again. [At least it worked for me] Hope it does for you too. Good luck~