Conversion from type 'DBNull' to type 'Date' is not valid

Description of Error:

When attempting to create an invoice associated with a dispatch the following error appears:

Conversion from type 'DBNull' to type 'Date' is not valid.

This error can also occur after upgrading ESC to a newer version if there are any dispatches that have been completed without a date in the date off field.

Cause of Error:

The dispatch that is being associated with the invoice does not have a valid Dispatch Date or Date Off.

Resolution:

Recall the dispatch you are attempting to invoice on the Dispatch Entry screen. Look for line items on the Schedule tab of the associated dispatch that have a Disp Time or Time On value but nothing in the Dispatch Date field or a time in the Time Off field but nothing in the Date Off field. Enter a valid date in those fields and save the dispatch. After doing this you should be able to create the invoice without any errors.

If a date does appear in those fields, it is possible that it is not formatted using the standard US format of mM/dD/YYYY. If that appears to be the case, please see this article for full details on how to fix it.