Polygon’s zkEVM network suffered an outage for 10 hours on March 23, which the team attributed to an issue with the blockchains sequencer due to a Layer 1 chain reorg.

Ethereum Layer 2 network Polygon’s zero-knowledge Ethereum Virtual Machine (zkEVM) chain was down for more than 10 hours over the weekend, according to data from the block explorer. 

The Polygon team confirmed the outage in an X post on March. 23, noting that the issue was confined to the rollup chain, which has been in its beta version since its launch last year, with all other chains running on Polygon’s chain development kit functioning as per normal.

Polygon zkEVM Mainnnet Beta faced an issue with its sequencer due to an L1 reorg. We are working on fully resolving the issue and will follow up with a detailed post-mortem.

This only impacts Polygon zkEVM (which is the only rollup) and does not impact Polygon PoS, Polygon CDK,…

— Polygon | Aggregated (@0xPolygon) March 23, 2024

With a more detailed post-mortem still to come, the team revealed that the root cause of the problem was with the block sequencer during a Layer 1 chain reorg. The block sequencer is responsible for packaging ordered transactions into a block. A chain reorg takes place when validators disagree on the most accurate version of the blockchain, resulting in the removal of a weaker duplicate chain.

In an update on March 24, the team said that the chain’s emergency council had activated the “emergency state” to allow the core team to fix the issue and allow the zkEVM mainnet beta chain to resume operations.

“Upon completing this upgrade, the emergency state was deactivated, meaning any further updates to the system are subject to a 10-day timelock before taking effect,” said the team. 

Polygon’s zkEVM was the first fully EVM compatible chain to hit the mainnet when it was launched, but data from The Block shows that it has failed to gain the same amount of traction as some of its rival layer 2 zk rollup chains in terms of transaction activity. However, Polygon’s Proof-of-Stake (PoS) chain saw its transactions increase 93% in the latest quarter, with Total Value Locked (TVL) rising to $1.1 billion, according to data from Messari. 

“Polygon has great tech. We shouldn’t let a sequencer failure sour any reputation. It happens, bugs happen, it’s early tech,” commented Fuel Network CEO Nick Dodson on X.