Hm, could be lot of things, check this ones:
-if you edited or transfered "young players" to any team with cm10 or mm10, the game will hang up at the end of the season
-check leagues you had imported with cm10, check calendar dates, check if any team had an specific stadium assigned on those leagues
-Did you expanded the database before importing new leagues with cm10?
-Check with cm10 if you imported a new league, if it was imported correctly, i mean, that league id and tournament id are linked, qualification rules are correct (x ex: southamerican leagues and libertadores cup, if the links for that cup are correct), no overwritted teams or teams in other leagues (x ex: imported argentinian league but Estudiantes is on a Polish league overwritting one of those teams)