I'm actually having a different issue.
At first, I left the V2 "DMX Engine" master driver in place, and just used the V3 "Universal Dimmer" driver. Things worked as expected. I was able to control the loads using the new drivers, etc.
Next, I replaced the V2 version of the "DMX Engine" driver with the new V3 version. In Composer, I connected the serial port of my controller to the new DMX engine. It shows online, etc. But, none of the loads are working. I can use the "All channels on" action of the driver and all of my lights do come on, but I'm unable to get individual channels to work via the other drivers. If I use the "Show DMX devices" action, every channel says "No device."
I rebooted the DMX engine and the controller. Any ideas?