Cannot apply Credit Memo to Invoice

 Hi everyone,

I tried to apply Credit Memo to Invoice by using Actions > Applications.

But when I select the Invoice at Apply To field, I got the error "You cannot increase the balance of this transaction"

I have checked the setup of Transaction Type and found the following config:

Creation Sign = Positive Sign

Natural Application Only = uncheck

Allow Overapplication = check

These configurations are the same as the other operating units but I don't know if there's anything else should I check.

Could you please advise?

Thanks,

Ying