I have had no problem running my machine in Easel. Here is my problem, when I tried to reset the 0 positions in UGS, I got an error saying that was an unsupported command. How do I get UGS to allow me to zero the machine at my work piece? Any ideas would be appreciated.
Shot in the dark here, because I don’t have a running machine to try it on yet, but I can think of two things right off the top of my head that might be happening. First is that the g-code you’ve generated is trying to send a homing command that grbl doesn’t recognize. Grbl will only respond to the “$H” command for homing. Second, if the correct command is being sent, it’s possible that the soft homing function is disabled (this is the default setting) on your grbl controller. Have a look at the Configuring Grbl page to see what commands are supported, and get an idea of how to change them.
Hope that’s even partially helpful! 
edited to add - This UGS bug page may also provide a faster fix.
Aaaaaaand, another edit… after downloading the latest UGS (v1.0.8) and trying it out on my Arduino that’s flashed with grbl, UGS just responds with “OK” when I press the “Reset Zero” or “Return to Zero” buttons. If you’re not running the newest version, that might be the problem too. I found UGS 1.0.8 here.
I hope at least one of these things works for you - I hate seeing problems go unsolved. 
I had the exact same problem with 1.0.7. Crashed it into the rails pretty hard with the homing command too. Upgrading to 1.0.8 solved the issues.