Error "Object reference not set to an instance of an object" when previewing in EngageOne Designer

Product Feature: Advance Preview/Preview
Versions affected: Doc1 Designer V5.x, V6.x


Previewing generates the error "Object reference not set to an instance of an object" in EngageOne Designer (V5.x and V6.x)


This is a generic error, and the most likely cause is that the "preview" production job has been deleted.


UPDATED: June 14, 2019
If this has been deleted, and no purge has been run, the "preview" production job will be found in the recycle bin in the "Project Explorer" tab in Doc1 Designer (V5.x) 

If you attempt to restore the "preview" production job from the trash, it will append the name of the preview job with a date and time stamp, which will still cause preview to fail, but with a different error.

With V5.x of Doc1 Designer, there is a SQL script to restore this job (quote DOC-6739), with V6.x, you can merge the preview production job from another strand to rectify this, alternatively, you should still be able to perform an Advanced Preview.

If this does not resolve the issue, please contact software support through the usual channels.