pls help me

Hi,
i bought Mateo Musacchio with 48 mothly installmently. But he came my club. But he seems free agent. i can use he. but he seems free. he can play with my club on match. other teams bid to mateo. i offer contact to mateo, he accept to me. but he still seems free.

He may seem free because you haven't paid anything up front for him. If you check finances then you should see a monthly cost in transfers being taken out. Also check player clauses to see if he has a monthly instalment price to his name.
(I don't know your experience of playing the game so I'm sorry if you checked these already.)

Maybe its the type of contract you have offered him? or length of contract?

seems odd to me never had that kind of trouble before. Could well be the type of contract given to him or a bug in the game.

I think its what contract you offered him.

not had the cash to pay by monthly installment but It could be a bug - I wouldn't count that out. Is there no way you could load an old save game or something and see perhaps?