This is because you have two folders for 109 cockpits in MODS enabled at the same time, which conflict with each other:
AAA_Cockpits_BF_109F_Default
AAA_Cockpits_BF_109F_Freddy
Enable one or the other, not both.
Scroll down to bottom of this post and look at the image there of the MODS folders. Take note of the coloured highlights showing which folders should be disabled.
(The link is inoperative)
This should all have happened automatically during install of U.I. 1.2, but it seems something went wrong with your install, did it?
Now I can stop this problem.
Thanks for help!