There will be an error in the files F-engrave produces due to the G64 code. The error is from F-engraves. Please open F-engrave and go to the menu Settings>>General Settings. When the dialog window opens,  find the line: G17 G64 P0.001 M3 S3000 and change it to G17.  and then save. For the g-code files that are already written, you can open them in Word-pad and edit this line