"The transaction about to be reversed is not in your transaction list"
Reversal transactions are used to correct errors in transactions that you've downloaded from your brokerage.
If the transaction containing the original error is no longer in your transaction list, Quicken warns you before allowing you to accept the reversal. If you get this error message, it may mean that you've already deleted the original transaction containing the error. If this is the case, then you can safely delete the downloaded reversal.
Click Yes to delete the downloaded reversal transaction.