Parity and Geth, Ethereum’s two main clients, went out of synch at around 3PM London time today, accidentally creating two chains operating in parallel. As such, Ethereum’s blockchain currently is not in consensus. Users, especially exchanges, are strongly urged to refrain from transacting or to wait for a very high number of confirmations until the matter is resolved.
Developers are currently working as a matter of urgency to resolve the issue with a solution to be expected within hours.
Nick Johnson, one of the main developers of the Geth client, stated to CCN:
“The root cause is an edge case around the state clearing; if an empty account is ‘touched’ so that it would normally be removed, but the call that ‘touched’ it goes out of gas, Geth will still remove that account from the state, while Parity will not.
The EIP doesn’t explicitly state one or the other is correct, but everyone’s agreed that Parity’s implementation makes more sense. Not explicitly spelling this out in the standard, and not writing a consensus test for this edge-case