I regularly get the following Error in VMD while cutting " IHS Error: Failed to detect material surface. Check work ground." This error occurs intermittently but when it does i can't find what causes it. I check grounds, move the ground clamp, clean the material, clean the torch head, move the material on the table i even cancel the program and start over. Each of the above items works occasionally but there's time when none of them work. Today for example i cut out 2 program with no issues then the error occurred and i was unable to rectify with the above steps. Does anyone have any experience with this error?