I was experiencing issues with harmony 16 premium, I have a gtx 1070 video card and had 2 4k monitors plugged into the 2 DV ports, I unplugged one monitor and harmony stopped crashing, I also made sure windows 10 was up to date and the graphixs drivers on the gtx 1070. hope this helps anyone else having issues. I was not aware harmony was graphics card heavy.
Running TWO 4K displays is demanding of a graphics card. Two displays of any resolution is not officially supported in Harmony but aside from a couple of minor workarounds the software works fine. I am pretty sure there is a limit to a task before something starts to show up but it is not unmanageable.