Error - 'Conversion from type 'DBNull' to type 'String' is not valid.' when submitting a Project Commencement

This is likely caused by an error in the auto generate project SQL Stored Procedure.
​
To resolve this issue Support will need to investigate the stored procedure that is being called during the process of submitting. Therefore please raise a new case online and reference the title of this article and please include details of the project trying to be created.