When entering new services, I was having this error, and I couldn’t figure out why:
Checking Table 'service' ERROR: 10813...service(number=XXXXXXX): Nextusagedate is '0000-00-00' (FIX MANUALLY)
BillMax support promptly acknowledged that it is a bug that cause this behavior under rare circumstances. The solution is to run on the billmax database the following SQL:
update service set nextusagedate=invdate where number=<XXXXXXX>;
