In the Account Combination, does the "*" in the Organization implies that this applies to all organization within the client?
*-21100-_-_ for Accounts Payable, does this mean that this account applies to all organization?
If a transaction is created and posted with * as the Org value then it will be an error.
Normally the appropriate org value from the document will be substituted in place of the *. Note that a bank account is owned by an Org and that Org value will be used regardless for that bank accounts transactions accounts posting.
Sometimes a GL transaction with an org of * was created if the user was logged in with an Org of * and then something like a payment was entered and then a new document like a "Payment allocation" was auto-created in the background .. it seemed to pick up the users logged-in Org of * . This is probably fixed in recent versions.