I ran into a problem using carbide create and UGS. When I uploaded a file and hit run it would immediately halt the operation. After some research on the forum I opened the code in notepad and deleted the Mcode which according to the forum is a tool change. Now the project runs without a hitch.
One curious thing though??? Shapeoko’s do not have tool changers, so why would this code be generated?
Anyway just thought I’d share my discovery in case someone else runs into the issue.
@MRay It is a curious thing isn’t it? I can’t think of why they decided to leave in the M code generation other than maybe they wanted to keep their options open for future machines 
It is. I am using carbide create for now but plan to move on to fusion 360 once I am a bit more comfortable. Do you know if there is any issues with UGS and fusion for future reference?
No, Fusion has a lot more control over the g-code output by having a list of user-selectable post-processors; this allows you to select one which doesn’t contain m-code commands.
If you’ll be using Carbide Create for the time being, I made a forum post which outlines how to make UGS ignore these commands permanently without further manual intervention: Permanent fix to "An error was detected while sending 'M6..."