I have no hacks n my game and after I installed the Seasons, When I am playing on university I go to the final exams, but when my sim comes back, he´s back again to the beginning of the period.
Like, If he just started university and was on the first half of the first year, when he comes back of the final exam hes back again to the begining of the first half of the first year.
He doesn lose any ability or nothing he got during this period, but hes just back again where he was, so I cant take my sims out of university T_T
Does anybody knows how to help me?
Big thanks!

Is it a specific sim/lot or all of them?
Try making a few test sims and see if you can get them past the first term

If it's a specific lot/sim then I'm afraid they're corrupted. I would recommend trying to get them to drop out.
Or if you're happy with cheats/hacks you could download the university clock from MATY and advance them the term they can't get past and see if it's ok from there. Or donload the insimenator, get them to drop out then set their age as teen again and try taking them to university again.

If it's all your sims then try using the Clean Installer to ensure that no hacks have hopped along with anything else you downloaded