X-carve error

gday guys iv run into a bit of a problem i keep getting a message that reads as follows detected error communicating with the machine and i cant figure out what it could be iv restarted the machine and my laptop and when i fire it back up all is good for a few minutes i run the homing cycle and all is good the i send g28 to the machine and then that message comes up but still runs the cycle and sometimes it just comes up by it self has this happened to anyone before all my settings seem to be right although this morning i was playing around testing out some feed speeds could that have anything to do with it could i have ran it to quick iv have also done a new machine set up hoping to start fresh but still no luck iv made sure all connections to x-controller and to stepper motors are right iv also tried $20=1 for sof stop but makes no difference im at a loss here and dont know what to do any advice will be much appreciated