I see 2 problems as posted. Block N10 has the letter O instead of number 0. X78 has 2 decimal points after it. I've never used G41/G42 so I don't know if there is a problem with that. I assume you have used G71 cycles on this lathe before. If not, maybe it takes a 1-block instead of a 2-block call. How old is the lathe? All newer ones I've ever programmed all use the 2-block call.