Publishing Error : Worker being stopped due to error return from conversion

Continuing to have issues with a Process Assembly. The model tree is straight forward, the Process Assy has a single object in the model tree (another assembly). That child assembly can publish with zero problems, however the Process assembly fails every time. Has anyone experienced the issue displayed by the log below:

2017-12-15 10:51:45	Successfully copied all files
2017-12-15 10:51:45	Sending $JOB$ D:\cadworker\cadworker1\w2i1j1520\_wvsjob.paj

2017-12-15 10:51:45	Time out disabled
2017-12-15 10:52:19	Reply from worker $ERROR$ Helper: Connection to worker has been closed. Shutting down... 
2017-12-15 10:52:19	Worker being stopped due to error return from conversion
2017-12-15 10:52:19	Sending reply by socket $ERROR$ Helper: Connection to worker has been closed. Shutting down...