This soft warning indicates that this transaction is identical to a transaction that has already been posted to the same account. Note that reconciliation is normally the best indicator of whether or not a transaction should be deleted. If the position has been balanced in reconciliation, then this warning can be safely ignored. Click here 
for more information on removing duplicate transactions when posting.
First, determine whether the transaction in the blotter is a duplicate of one that has already been posted. Do the following:
From the main Morningstar Office window, select the Portfolio Management tab.
From the Accounts page, double-click the account in question to open the Account window.
From the Account window, select the Transactions page.
Locate the posted transaction, if possible. If the transaction is found, return to the Blotter window and delete the transaction from there (see directions below). If it is not a duplicate transaction, you can post the transaction to your practice.
If you determine that the transaction on the blotter is indeed an unnecessary duplicate, delete it from the blotter. To delete the transaction, do the following:
From the Transaction page on the Blotter window, select the transaction.
Click the Action menu above the spreadsheet area.
Select Delete.
When the confirmation message appears, click Yes.
Click the Save icon.
When the confirmation message appears, click Yes.
See Also
Handling Warnings in the Import Blotter