Hi I'm getting a

Peer 178.143.67.69:29235 disconnected us: You offered us a block that we reject as invalid
Peer 178.143.67.69:10585 disconnected us: You offered us a block that we reject as invalid
Peer 178.143.67.69:11637 disconnected us: You offered us a block that we reject as invalid
Peer 178.143.67.69:12823 disconnected us: You offered us a block that we reject as invalid

Any idea what could this be?

EDIT (short answer): @dannotestein summarized: "If you're running a new client, it means this other client is an older one and you have nothing to worry about (the other guy needs to update his client). If you're not running a new client, you probably need to update.". Thx @xeroc for the answer too

Thanks,
Nico Cesar