Do you have another backup apart from this file looks like the data is corrupted. We can try restoring it. Send your contact details to support@servicedesk.com along with this forum link as reference.
Regards,
Priya K
SDP Support - FAQ
ServiceDesk Plus - Help Desk Software of your Choice
Regards,
Priya K
SDP Support - FAQ
ServiceDesk Plus - Help Desk Software of your Choice