Had the same problem. As long as I had a career I would CTS. The only time I did not CTS was in the academy. 2 and 2 = career problem. Went to my documents and deleted SHIII file. I then unloaded all mods (JSGM) and Started new career and everything was great. CTD's are caused by many things so I dont know how much help this will be if any.
Viel Glück Captain.