I think there's some bug at monero network.
Detailed info
https://bitcointalksearch.org/topic/m.18034060
Any idea?
Reposting what I said on Reddit:
Just to clarify, it's not a fork, and it does not appear to be malicious. A portion of nodes running 0.10.2.0 or 0.10.2.1 handled a reorg badly, leaving a hash->index entry in the database that should've been cleaned up, causing those nodes not to be able to sync past that block.
To reiterate: it is not a consensus issue, it is not a fork, and it does not appear to be malicious. It is a DB bug that affected a limited number of nodes.
At this time we are debugging it further, and will roll a new point release out when we have a fix.
A quick fix is to export and reimport your blockchain.