Revolving Credit Loans; Account Processes may fail with a "Failed to mark Contracted Payment as processed." error

Account Processes may fail with a "Failed to mark Contracted Payment as processed." error, and this message may include other unrelated details.

This was an issue to do with "Payment" Standard Transactions attempting to mark a Contracted Payment as paid - but Revolving Credit Loans do not use Contracted Payments, so this always failed.

In addition, the error message continued the existing error rather than starting a new error, which causes the message to be confusing.