Hi Kripisaxena,
Whatever scenario you are presenting is technically impossible. because once you are closing the connection it has to be close there is no other option. but the case might be like that the connection object is a class member and in whichever method you closed that connection might not executed due to some exception and if the try - catch is used its handled by the catch (So the Connection.Close() is not executed at all) and as the conn object is declared as class member you are using that method successively and you couldnot close the connection object in last call(which was handled by the catch) the connection is in open state so you will get the error.
How ever better to check the ConnectionState.
Thanks and Regards,
Rk_Hirpara