We have researched the issue and found that Billing errors were caused by missing transaction records which caused NULLs in the returned unapplied data. Entries were missing from transactions, transactions_archive, and transaction_detail tables.
We can restore the missing transactions entries using the transaction_history table, and transaction_detail entries using the previous backup made before the missing entries were removed.
However, we were unable to determine the cause why the transaction entries were removed in the first place. To find the cause of the issue we might need to add logging for transaction tables, which will require a TTX ticket.
Please let us know if we should create one.
Conversion from type 'DBNull' to type 'String' is not valid. : System.InvalidCastException: Conversion from type 'DBNull' to type 'String' is not valid.
at Microsoft.VisualBasic.CompilerServices.Conversions.ToString(Object Value)
at PAClaimsNew.frmSelTransPreClaim.cmdOK_Click(Object eventSender, EventArgs eventArgs)