Both relatively new to me cpu's, recent powerful units. One just purchased 2 wks ago when this happened last. The other was purchased this spring. Both reported by the dealer to be clean, safe and powerful. DataCAD 18.03.00.06
Is there a specific command that causes this? Does it happen in all drawings? If it's a specific function, does it happen with a new default file? Maybe look into adding Datacad folder and dcadwin.exe to your anti virus's list of exceptions.