Polygon Heimdall V2 Mainnet Faces 1-Hour Outage Due to Validator Exit

The Polygon Heimdall V2 mainnet, a consensus client for the Polygon proof-of-stake chain, experienced a temporary outage on July 30, 2025, beginning around 9:30 UTC [1]. The disruption lasted approximately one hour and was attributed to an unidentified validator exiting the network, according to Polygon spokespersons [2]. During this period, the Bor layer—responsible for block production and transaction execution—remained fully operational, producing blocks without interruption [3].

Polygon officials confirmed that the Heimdall mainnet has since been restored, and block explorers are in the process of re-syncing to display accurate data. However, post-recovery, some inconsistencies were observed across various RPC providers’ Bor nodes. The team is actively working with these partners to accelerate resolution. One provider has already returned to full functionality, though with slightly delayed synchronization [4].

This incident marks a recurrence of issues previously associated with the Heimdall consensus layer. In March 2022, Polygon experienced several hours of downtime due to a similar error in Heimdall V1, which was caused by validators operating on differing blockchain versions [5]. The recent Heimdall V2 upgrade, launched in early July 2025, aimed to address such vulnerabilities by reducing finality times to approximately five seconds and integrating newer technologies such as CometBFT and Cosmos-SDK v0.50 [6]. Polygon co-founder Sandeep Nailwal described the V2 upgrade as the “most technically complex hard fork” in the chain’s history since its launch in 2020 [7].

While improved finality and throughput are essential for scaling blockchain networks, they also introduce additional complexity and potential failure points. The recent outage highlights the challenges in maintaining consistent uptime as systems evolve. Consistent availability remains a core requirement for blockchain networks aiming to serve as a reliable, 24/7 alternative to traditional financial infrastructure [8].

Polygon’s status update confirmed that the Heimdall service was unresponsive as of 9:30 AM UTC on July 30, with the team actively investigating the issue [9]. Similarly, QuickNode reported a network-wide stall at block height 74,592,238, impacting all operations [10].

The event underscores the importance of robust testing and coordination between protocol developers and infrastructure providers to minimize disruptions and ensure seamless user experiences.

Source:

[1] [Cointelegraph](https://cointelegraph.com/news/polygon-hemidall-v2-mainnet-experiences-temporary-outage)

[9] [Polygon Status](https://status.polygon.technology/)

[10] [QuickNode Status](https://status.quicknode.com/)