Re: Whats wrong with the blockchain right now?

https://bitcoin.org/en/alert/2015-07-04-spv-mining

Miners generating invalid blocks. Wait for 30 confirmations? that will take a looooong time. Whats wrong and how worried should we be?

I think that was the blockchain split on the 4th of July, for more info refer to this thread: https://bitcointalk.org/index.php?topic=1108304.0