If you received a message that there has been an error and invoices have not completed successfully,
--DO NOT PANIC! It is advisable to press the OK button on this message box. The message appeared because Invoice program has been run since your last batch of printed invoices. The tickets processed in the incomplete run of the program has produced a batch of unprinted Invoices. To correct this situation, the invoice #'s associated with these tickets will be cleared. The program will begin with the succeeding number of the last printed invoice number. The program will then default the prompts to the last range run.

If printer is not available, windows will send back a cancel routine because it can not find printer. Did someone hit the cancel button? Is this a shared printer? Is computer on? Is printer on? Is sharing on? If printing cannot be achieved--reboot the computer.