Phoenix (0.9.8.0)
This mandatory hard fork release corrects a problem which allowed a recent block to enter the chain data store despite a missing transaction.
Also contains additional bug fixes from Monero (credit moneromooo and warptangent)
All nodes will require resyncing after installing this update. In addition any blocks that are part of the invalid chain starting at height 798358 will be rejected.
Nodes continuing to advertise the invalid blocks will be dropped and eventually banned. This may initially produce a high volume of error messages.
Wallet rescan may be necessary to recover coins spent in the invalid chain. Wallet rescan after resync is highly recommended in any case. To rescan, rename or move the wallet.bin file and start the wallet normally.