Ah, ok then... I did read those instructions...
(I'm one of those who always tries to RTFM!) I think this part made me think there was a subfolder with the UI mods:
Then there must be some other problem. I got CTD when starting a new career after removing all mods. I tried to start Coastal Waters and CTD'd. Then I tried the tutorial, it loaded, but as I clicked the first button to select a torpedo tube, it crashed too.
For now I went back to my old mod-soup, including TDW's UI and OHII v2. I've had problems using full OHII on my system ( I use only base plus ships, no env) so that could be a problem, I don't know. Will check again later, a super mod is so convenient, I hate mod-soups!