[tor-relays] warning in my relay log

I have changed server and tor version (from Tor 0.2.6.10 to Tor 0.2.7.5). My relay works but I have this warning: "http status 400 ("Looks like your keypair does not match its older value.") response from dirserver '208.83.223.34:443'. Please correct." This is my relay fingerprint: 59573AB90614D929360C7D9BCBF3313497A22AA2 What means and what I have to do? The keys for me is correct. Thanks for reply