When committing an event registration transaction batch, you might notice that a transaction errors and is sent to an exception batch with the error, "Nullable object must have a value".
This can happen if the credit card information does not make it into CRM. In batch, click on the affected transaction > Review transaction details > Payment > notice the Credit card number field is grayed out. Find the transaction in the EventTransactions table and enter the event registration and payment manually using the Transaction XML.
Contact Blackbaud Support and reference this article if you'd like assistance finding the transaction information.