Users of the Open Ethereum client encountered a consensus error after activating the Berlin hardforge and problems with the synchronization of the Ethereum blockchain. The error was resolved a few hours later. The planned Berlin hardfork was rolled out yesterday on a block of 12,244,000 on the Etherium network. The update included four suggestions to improve the current Etherium network and reduce commissions. 294 blocks after the activation of the hardforge, a consensus error occurred with one of the software clients, Open Ethereum, and the nodes using the client stopped syncing with the blockchain. Everyone running this client - about 12% of all nodes in Ethereum - could not use the blockchain until the error was corrected. The problem led to the disabling of the Etherscan blockchain explorer. The error was related to a transaction related to a smart contract that does not yet exist, but is planned for inclusion in a future update. Gnosis CEO Martin Köppelmann tweeted, "Thus, @OpenEthereumOrg processed the gas prices for this transaction somewhat incorrectly, which caused all subsequent problems (the block was rejected as invalid)." In other words, Open Ethereum priced one transaction differently than other software clients. This had the side effect of causing the Open Ethereum client (but not others) to reject an entire block full of transactions, and in this synchronization with the blockchain was disrupted. As a result, exchanges such as BitStamp and Coinbase temporarily suspended withdrawals of ETH and ERC-20 tokens.
According to Go Ethereum developer Marius Van Der Wijden, who helped solve the problem, the bug was not obvious, so it was not noticed during the testing phase of the update. The Open Ethereum team fixed the bug a few hours after it appeared. Keppelmann wrote, "After installing the updates, Open Ethereum nodes should be able to re-sync without any problems - re-syncing from the genesis block or manually deleting the block is not required."