VERIFIED SOLUTION i

As of MailStream Plus release 8.3.1, Dispatcher4™ is no longer supported.

Per the MSP 8.3.1 Release Announcement:
Note also that as of Release 8.3.1, Dispatcher4™ is no longer supported.
 
What this means is MSP 8.3.0 was the last version of MSP that a MS D4 GUI was available for.
 
If a D4 job has other products that are run with MailStream Plus, the g1j job will have to be edited to exclude the MailStream Plus step.
 
 
UPDATED:  April 5, 2017