Did some googling and found this on the Repetier forums…
To quote Repetier’s Response:
"It is a communication error.
checksum mismatch => The given checksum could not be verified.
Error:No Line Number with checksum => If we send a checksum we need also a line number. So the command got split on transfer in 2 halfes as it seems. One with line number and no checksum and the othe rhalf.
Host fixes these error automatically. I expect there is a Resend somewhere near the messages."
If its a communication error why does it only occur when I am trying to run raster engraving jobs. All my other vector jobs have run smoothly.