There have been a few instances where POS crashes while processing a payment for a transaction. In normal circumstances, this transaction is displayed when POS is started again and you are able to complete the transaction. It is possible that you may run into an instance where a payment such as a credit card was partially processed but not completely linked to the transaction. Thus the transaction will not allow you to accept a payment or void the payment/transaction and you are stuck. If you are simply looking to remove this recalled transaction from POS, you can find this stored transaction in the RETAILTRANSACTION table in the POS database with reference to the store and terminal ID that this is occurring on. The data is encrypted so you will not be able to see the specifics of this transaction.
You can delete this transaction from the table and it will no longer recall that transaction when POS is launched.
IMPORTANT NOTE: Keep in mind that if any part of the transaction did post, you will need to make the necessary adjustments either in POS or AX.