Identify the disadvantage of trial balance?

The trial balance may be wrong but it will not show it (total debit balances will still be equal to the total credit balances). It may happen if there are next kind of mistakes: Commission - a transaction is entered in the wrong account; Reversal - the debit entry in written on the credit side and the credit entry is written on the debit side; Ommision - a transaction is completely ommited from the books; Principle - an item is ebtered in a completely wrong class of account; Original entry - a wrong account is entered in a book of origibal entry and then the wrong figure is used for posting a ledger; Compensating - errors cancel each other.