For many rounds I’m trying to sub my MC+1 during the game and nothing happens. Until now only in this position that I’m facing this kind of problem.

what are you settings for the substitution?

Em qualquer partida, após o minuto 45, substituir jogador em zona M, lado C e mentalidade 1 por João Rocha.

Any match, after 45 minute, change player in M one, C side, mentality 1 by João Rocha.

Have you selected a player or "best position? Otherwise you will only change the position of the player on the field.

I’ve selected the player. it happens ONLY with the MC+1. All my subs are ok only when I put to sub some player into this position that nothing happen.

Just had a look at your matches and main formation, I can’t see anything wrong. The only situation where it should fail is if the player was unavailable (red card or injured), otherwise the sub should happen. I’ll have a look in the code later, see if I can find anything wrong when dealing with position MC1, but I’d be surprised to find an error that specific!