Hi, I get ETC, sometimes my rig reboots, and Claymor's log comes to an end with the line NULNULNUL... Sometimes one hour, and sometimes works and 30, I can't understand in what the reason. Somebody knows that he means if the ravine comes to an end with NULNULNUL...

Have you tried to re-download claymore?
Are you using the latest version? Maybe try another version and check if it gives you the same error...
Have you checked if you are using the right drivers?
everybody has same problem - just go check random address on etc ethermine org pool
cant understand this also
mining ETH is no problem
mining ETC is problem with same tools
looks like some kind of attack in ETC