3819249 - Why am I receiving the Unexpected System Error when trying to add a transaction to an Expense report?

The Error message is a generic one (pasted below.)
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Unexpected System Error. Please try your action one more time. If you encounter the error again, please forward all information, including the events leading to the system error, to your Expense Administrator.
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There is no item matched with the Transaction (mobile entry, itinerary etc...) OR inside the Expense report. The card transaction does not have any rich card data as well which rules out the possibility of automatic receipt creation.

User is receiving the Unexpected System Error when attempting to add a transaction to an Expense Report. , KBA , CON-CA , Cross Applications , CON-CA-ADM , Administration , Problem