Thx for the quick reply.
From the logs I attached here is the printer's FW
SENT: M115
READ: CMD M115 Received.
READ: Machine Type: dremel 3d idea builder
READ: Machine Name: DREMEL
READ: Firmware: v1.5 20180611
The attached logs implies nothing is coming back but I'm not sure about that. In my steps to get a print to start I have to start by having no printer added, then I added one and all is stable. I can send to the printer, when the machine control panel shows 'Disconnected' and a print starts. But if I exit S3D and restart it (now I have a printer added AND my printer is still connected and idle) within 5 to 10 seconds S3D crashes even without opening the machine control panel or sending anything to the printer. If I open the panel I can see it says 'Disconnected' and then 5 to 10 seconds late it crashes. I get similar results if I start S3D (with the printer added) and then connect and power up my printer. Somehow the printer being connected but idle crashes S3D.
It seems once S3D is expecting replies that is does not think are coming back, any actions I request thru S3D get sent out (I see flash of commands in the communication box) but a crash occurs and I cannot get those logs.
So, bottom line something is up and something is happening between the two on the SECOND attempt. If I delete the printer and re-add it and never use the machine control panel to connect everything is stable. In fact if I use the control panel and connect and then disconnect very quickly things remain stable, the M602 command goes out and is responded to by the printer (see new attached file).