zkSync Era, a popular layer-2 (L2) blockchain, restored block production after a network glitch disabled new blocks for close to five hours, according to an admission by the project’s developers on X. The interruption was the second network outage in eight days, underscoring reliability challenges for the L2 even as it continues to attract users and activity.

What Happened

The development team said an automated safety protocol on the network was affected by a server bug. The issue was fully resolved, and the team committed to publishing a post‑mortem report detailing the root cause of the disruption.

Operational indicators during the incident reflected a temporary loss of liveness. The blockchain’s status page showed a “major outage” label before reverting to “operational” once service resumed. Consistent with that timeline, zkSync Era’s block explorer recorded the last processed transaction at 10:53 UTC on 25 December, with the final batch submitted to the Ethereum network at the same time.

This episode followed an earlier halt in block production on 16 December, making it the second disruption within an eight‑day span. The brief but notable frequency of events places heightened attention on the project’s forthcoming post‑mortem and its approach to avoiding a repeat.

Technology Overview

zkSync Era launched earlier in the year as the first Ethereum Virtual Machine (EVM)‑compatible zero‑knowledge rollup (zk‑rollup) to go live on mainnet. Since its debut, the network has moved quickly up the leaderboard of Ethereum scaling solutions, surpassing competitors such as Starknet and Polygon zkEVM.

Adoption metrics reflect that trajectory. Based on L2Beat data analyzed at press time, zkSync Era held the fourth‑highest total value locked (TVL) among Ethereum scaling projects, with around $573 million deposited. That level corresponded to a little over a 3% share of funds across L2 networks.

Performance indicators have also been steady. The blockchain maintained a transaction throughput of about 10 transactions per second (TPS) over time, and in the prior 24 hours it ranked as the fastest Ethereum L2, with a TPS of 14.26.

How It Works

As an EVM‑compatible zk‑rollup operating on top of Ethereum, zkSync Era processes user activity on its own network and submits batches to Ethereum for settlement. The progression from processing to batch submission is visible in public tooling: during the outage window, the block explorer’s final transaction and the last batch sent to Ethereum were both timestamped at 10:53 UTC on 25 December, aligning with the observed pause in block production. Following remediation of the server‑side bug that affected an automated safety protocol, block creation resumed and the status page returned to “operational.”

Throughput figures provide additional context around network behavior outside of incident windows. A sustained rate near 10 TPS indicates a consistent baseline of processing capacity, while the recent 14.26 TPS reading over 24 hours highlights periods of faster activity. These performance snapshots complement TVL as indicators of how actively the network is being used and the scale of assets that participants have entrusted to it.

Industry Impact

Outages on scaling networks can ripple through user experience, as pauses in block production disrupt the cadence of transaction inclusion and batch submission. In zkSync Era’s case, the halt lasted close to five hours before normal operations were restored. Because this was the second such disruption within eight days, attention naturally shifts to the resiliency of the network’s safeguards—particularly the automated safety protocol implicated by the server bug—and to the clarity that the promised post‑mortem is expected to provide.

Even so, zkSync Era’s trajectory since launch has been notable. The network’s position among the top L2s by TVL, its more than 3% share of L2 deposits, and its recent TPS measurements present a picture of sustained use and competitive performance. Its standing relative to Starknet and Polygon zkEVM further illustrates how quickly it has advanced within the cohort of EVM‑aligned zk‑rollups and other Ethereum scaling efforts.

The rapid shift on the status page from “major outage” to “operational” underscores the role of incident response and visibility. Public status indicators and explorers provided immediate signals to users during the event, from the last recorded transaction and batch time to the restoration of functionality. Such transparency is important for developers and users who rely on timely feedback when activity stalls and when it resumes.

Future Implications

The development team’s pledge to publish a post‑mortem sets expectations for a technical accounting of the server bug and its impact on the automated safety protocol. With two outages occurring in quick succession, details on remediation steps will be closely watched by participants who track uptime, transaction finality, and overall liveness across L2 environments.

At the same time, the network’s broader performance context remains part of the assessment. zkSync Era’s early‑year mainnet launch as the first EVM‑compatible zk‑rollup, its growth to the fourth‑largest TVL among Ethereum scaling solutions, and its recent throughput readings—including a 14.26 TPS pace over the last 24 hours—frame the scale at which the network is operating. The combination of these metrics and the forthcoming post‑mortem will shape how stakeholders evaluate operational maturity alongside usage and growth.

For now, zkSync Era is back to normal operations following a close to five‑hour production pause, with network indicators reflecting recovery from a “major outage” status to “operational.” The developers’ acknowledgment of the issue, the attribution to a server bug affecting an automated safety protocol, and the commitment to share a post‑incident report define the current state of play as the L2 continues to compete near the top tier of Ethereum scaling platforms.