On Tuesday, Ethereum (ETH) developer Tim Beiko tweeted that Kiln successfully passed the Ethereum Merge, with validators producing post-merge blocks containing transactions. Kiln will be the last Merge testnet (formerly Ethereum 2.0) before existing public testnets are upgraded. "Merge" involves taking Ethereum's Execution Layer from the existing Proof of Work layer and merging it with the Consensus Layer from the Beacon chain, turning the blockchain into a proof-of-stake network. The Foundation writes:

However, it appears not everything went according to plan during testing. According to Kiln Explorer, there were several errors relating to contract creation. In a follow-up tweet, Beiko said a client was not producing blocks consistently, though "the network is stable, with >2/3rd of validators correctly finalizing." A fellow Ethereum developer, Marius Van Der Wijden commented on the matter as well, pointing out that Prysm was proposing bad blocks during the transition on Kiln.

Prysm is a Go programming language variant for implementing Ethereum Consensus specification. As told by Van Der Wijden, it turns out one block had the incorrect base fee per gas value, and substituting it with the actual expected base value appears to have solved the problem. On its official roadmap, the Ethereum Foundation states that the Merge upgrade will be shipped by the end of Q2 2022. However, a few features, such as the ability to withdraw staked ETH, will not be available immediately after the Merge, as developers concentrate their efforts on the latter.

And it seems to have worked Post-merge blocks are being produced by validators, and they contain transactions! https://t.co/xearnsuZFpJust waiting on finalization now