tag:status.unichain.org,2005:/history Unichain Status - Incident history 2026-03-05T23:00:06.339+00:00 Unichain tag:status.unichain.org,2005:Incident/cmme2j9vf000l11emh0k10rlf 2026-03-05T23:00:06.339+00:00 2026-03-05T23:00:06.339+00:00 Unichain Sepolia Unsafe Head Stall Type: Incident

Duration: 18 hours and 48 minutes

Affected Components: L2 Block Production, Flashblocks Websocket Stream, Public RPC, L1 Batch Posting, , Node Syncing, Unichain Sepolia →

Mar 5, 23:00:06 GMT+0
Investigating - We are currently investigating this incident..

Mar 5, 23:50:33 GMT+0
Identified - Fix implemented, recovery in progress..

Mar 5, 23:53:52 GMT+0
Monitoring - Block production has resumed without flashblocks. We are working on recovering flashblocks..

Mar 6, 17:48:27 GMT+0
Resolved - This incident has been resolved..

]]> tag:status.unichain.org,2005:Incident/cmiqogerv02pkfqco435uzb9e 2025-12-03T23:00:00.000+00:00 2025-12-04T01:48:56.786+00:00 Unichain Mainnet: Post-Fusaka Safe Head Stall Type: Incident

Duration: 3 hours and 33 minutes

Affected Components: Flashblocks Websocket Stream, L2 Block Production, Public RPC, L2 Block Production, Flashblocks Websocket Stream, Node Syncing, L1 Batch Posting, Public RPC, L1 Batch Posting, , , Node Syncing, Unichain Sepolia → Unichain Mainnet →

Dec 4, 01:48:56 GMT+0
Identified - After working with OP Labs, we have identified both an issue in our batch submission and in the consensus client handling of such a case. We are trying to roll out a new version of the consensus client that fixes this issue..

Dec 4, 02:32:32 GMT+0
Monitoring - We implemented a fix and are currently monitoring the result..

Dec 4, 02:32:46 GMT+0
Resolved - We have identified that the root cause of the safe head stall on Unichain Mainnet is due to a bug in how op-node handles fetching blobs. All nodes operators will need to update their op-node to`us-docker.pkg.dev/oplabs-tools-artifacts/images/op-node:e1db990da90a845e1943b1dc20f59e18099db538`.

Dec 4, 02:40:49 GMT+0
Postmortem - Unichain Mainnet erroneously posted the same batch transaction at two different nonces. This triggered a corner case in the consensus layer client that made it impossible for the L2 Safe Head to progress. OP Labs has a fix available: [us-docker.pkg.dev/oplabs-tools-artifacts/images/op-node:v1.16.3](http://us-docker.pkg.dev/oplabs-tools-artifacts/images/op-node:e1db990da90a845e1943b1dc20f59e18099db538). Please upgrade your consensus layer clients on Unichain to use this image until OP Labs provides a newer release..

Dec 3, 23:00:00 GMT+0
Investigating - We are currently investigating this incident..

]]> tag:status.unichain.org,2005:Incident/cmi1vita8005dfg4en1srqgm9 2025-11-16T15:31:43.843+00:00 2025-11-16T15:31:43.843+00:00 Unichain - L2 Batches are not being submitted to L1 Type: Incident

Duration: 35 minutes

Affected Components: L1 Batch Posting, L1 Batch Posting

Nov 16, 15:31:43 GMT+0
Investigating - We are currently investigating this incident..

Nov 16, 15:47:49 GMT+0
Identified - We have identified an upstream issue with our TEE signers that has made batch posting functionality flaky..

Nov 16, 16:06:13 GMT+0
Resolved - This incident has been resolved..

]]> tag:status.unichain.org,2005:Incident/cmhz96d4500nkrz0fk81sivx8 2025-11-14T14:30:00.000+00:00 2025-11-14T14:30:00.000+00:00 Unichain Mainnet: Transactions are not being included in new blocks Type: Incident

Duration: 4 hours

Affected Components: Public RPC, L2 Block Production, Node Syncing, L1 Batch Posting, L1 Batch Posting, L2 Block Production, Public RPC, , , Node Syncing, Unichain Sepolia → Unichain Mainnet →

Nov 14, 14:30:00 GMT+0
Investigating - We have noticed that many transactions are getting stuck within Unichain Mainnet's mempool and are subsequently not being added to newly produced blocks. This means user swaps and regular transactions are not being submitted to the chain..

Nov 14, 17:00:00 GMT+0
Identified - Many users are reporting that their swaps and transactions are stuck. We have identified an issue with Unichain's proxy where it is not forwarding transactions to our TEE builder..

Nov 14, 18:30:00 GMT+0
Resolved - This incident has been resolved. An upgrade to the TEE builder had a poor interaction with our proxy, leading to transactions not being submitted properly..

]]> tag:status.unichain.org,2005:Incident/cmhji1s4p00k0148tuan0prn3 2025-11-03T17:00:00.000+00:00 2025-11-03T17:00:00.000+00:00 Unichain Mainnet Safe Head Stall Type: Incident

Duration: 4 hours and 9 minutes

Affected Components: Node Syncing, Public RPC, L2 Block Production, Public RPC, L1 Batch Posting, L2 Block Production, , Node Syncing, , L1 Batch Posting, Unichain Mainnet → Unichain Sepolia →

Nov 3, 17:00:00 GMT+0
Identified - We are continuing to work on a fix for this incident..

Nov 3, 18:22:17 GMT+0
Identified - We are continuing to work on a fix for this incident..

Nov 3, 19:11:34 GMT+0
Monitoring - We are posting batches, but our internal beacon chain RPC is having issues. Internal rollup nodes are unable to derive from L1, but the safe head is being advanced on-chain..

Nov 3, 20:36:57 GMT+0
Monitoring - We've identified a fix and are rolling it out. Some rollup nodes are starting to recover on mainnet already..

Nov 3, 21:09:05 GMT+0
Resolved - This incident has been resolved..

]]> tag:status.unichain.org,2005:Incident/cmgb56k8201ghhrwxqujgmyji 2025-10-03T17:52:39.410+00:00 2025-10-03T17:52:39.410+00:00 Safe head stall and withdrawals delayed on Unichain Mainnet and Sepolia Type: Incident

Duration: 3 hours and 56 minutes

Affected Components: Public RPC, , Node Syncing, L1 Batch Posting, Node Syncing, Public RPC, , L2 Block Production, L1 Batch Posting, L2 Block Production, Unichain Mainnet → Unichain Sepolia →

Oct 3, 17:52:39 GMT+0
Identified - We are continuing to work on a fix for this incident..

Oct 15, 17:37:20 GMT+0
Postmortem - <https://uniswaplabs.notion.site/Public-Postmortem-Unichain-Mainnet-and-Sepolia-Safe-Head-Stall-Withdrawal-Delay-28dc52b2548b802c89b7cb36af3e16e5>.

Oct 3, 19:42:36 GMT+0
Identified - We are continuing to work on a fix for this incident..

Oct 3, 21:18:15 GMT+0
Identified - We are continuing to work on a fix for this incident..

Oct 3, 20:30:16 GMT+0
Identified - We are continuing to work on a fix for this incident..

Oct 3, 21:32:57 GMT+0
Monitoring - We implemented a fix and are currently monitoring the result. The safe head is currently catching up..

Oct 3, 21:48:21 GMT+0
Resolved - This incident has been resolved..

Oct 3, 18:33:47 GMT+0
Monitoring - We've identified a fix and are currently deploying and testing it..

Oct 3, 19:18:15 GMT+0
Monitoring - Still working on current fix..

]]> tag:status.unichain.org,2005:Incident/cmeltlid10002ditoqktih1f6 2025-08-21T19:37:00.000+00:00 2025-08-21T19:37:00.000+00:00 Flashblocks down on Unichain Mainnet Type: Incident

Duration: 13 minutes

Affected Components: L2 Block Production

Aug 21, 19:37:00 GMT+0
Investigating - We are currently investigating this incident. Flashblocks are not being produced, but blocks are still being produced on the 1s block time..

Aug 21, 19:50:00 GMT+0
Resolved - This incident has been resolved..

]]> tag:status.unichain.org,2005:Incident/cmcvcwdwv001oc3nwefxc4k17 2025-07-09T01:20:00.000+00:00 2025-07-09T02:30:00.000+00:00 Unichain Mainnet - Batcher not submitting and safe head stall Type: Incident

Duration: 15 hours and 15 minutes

Affected Components: L1 Batch Posting

Jul 9, 02:30:00 GMT+0
Resolved - L1 Batch Posting is now functional. L2 safe head is advancing..

Jul 9, 15:34:00 GMT+0
Investigating - L1 Batch Posting is unable to connect to the active sequencer and is not posting batches to L1\\. L2 Safe head is stalled..

Jul 9, 15:45:00 GMT+0
Resolved - This incident has been resolved..

Jul 9, 01:20:00 GMT+0
Investigating - L1 Batch Posting is unable to connect to the active sequencer and is not posting batches to L1\. L2 Safe head is stalled..

]]> tag:status.unichain.org,2005:Incident/cmcn4jc6f005h9mhuwe0kew7g 2025-07-03T08:29:00.276+00:00 2025-07-03T09:53:57.796+00:00 Unichain Sepolia Batcher is Not Producing Batches Type: Incident

Duration: 1 hour and 25 minutes

Affected Components: , L1 Batch Posting, Unichain Sepolia →

Jul 3, 09:53:57 GMT+0
Resolved - This incident has been resolved..

Jul 3, 08:29:00 GMT+0
Investigating - We are currently investigating this incident..

Jul 3, 09:49:22 GMT+0
Monitoring - We implemented a fix and are currently monitoring the result..

]]> tag:status.unichain.org,2005:Incident/cmbk7yqxu002dnk4624sd5jdo 2025-06-06T02:22:00.000+00:00 2025-06-06T02:22:00.000+00:00 Unichain Mainnet Unsafe Head Stall Type: Incident

Duration: 8 minutes

Affected Components: Node Syncing, L2 Block Production, L1 Batch Posting, Public RPC

Jun 6, 02:22:00 GMT+0
Identified - Unichain Mainnet sequencer stalled for almost 10 minutes during planned maintenance period..

Jun 6, 02:30:00 GMT+0
Resolved - Active sequencer is restarted and unsafe head is progressing..

]]> tag:status.unichain.org,2005:Maintenance/cmazu0pjy004docwbvjy5cyic 2025-05-22T20:33:03.755+00:00 2025-05-22T22:49:57.372+00:00 Unichain Infrastructure upgrade Type: Maintenance

Duration: 18 hours and 56 minutes

Affected Components: Public RPC, Node Syncing, Node Syncing, L2 Block Production, L2 Block Production, L1 Batch Posting, Public RPC, L1 Batch Posting

May 22, 22:49:57 GMT+0
Identified - Maintenance is taking longer than estimated. Unichain Sepolia is almost finished upgrading the fleet and Unichain Mainnet is pending. The Maintenance period will be increased by 2 hours..

May 22, 20:33:03 GMT+0
Identified - We are upgrading the machines running our various rollup nodes to be able to handle Unichain's growth for the foreseeable future. We do not expect any outages or downtime in this period, but large upgrades such as this can have impact on chain performance if something goes wrong..

May 23, 15:29:33 GMT+0
Completed - Maintenance has completed successfully..

]]> tag:status.unichain.org,2005:Incident/cmanb3h7k003711hg74gruc70 2025-05-14T01:10:00.000+00:00 2025-05-14T02:26:28.449+00:00 Unichain Sepolia - Safe Head is stalled due to L1 Batcher Degradation Type: Incident

Duration: 3 hours and 18 minutes

Affected Components: L1 Batch Posting, Public RPC, Node Syncing, Node Syncing, L2 Block Production, L2 Block Production, L1 Batch Posting, Public RPC

May 14, 02:26:28 GMT+0
Monitoring - L1 Batches are being regularly posted now and the backlog of L2 transactions is being reduced..

May 14, 01:10:00 GMT+0
Identified - The infrastructure supporting the L1 Batcher has began OOM'ing. Engineers have identified a fix and are deploying it, currently..

May 14, 04:27:51 GMT+0
Resolved - All systems are operational and L1 batches for all transactions over the incident period have been submitted to the L1..

]]> tag:status.unichain.org,2005:Incident/cm8qdz9qm000fhz5swmjkwtux 2025-03-26T20:25:00.000+00:00 2025-03-26T20:25:00.000+00:00 Unichain Sepolia Unsafe Head Stall Type: Incident

Duration: 13 minutes

Affected Components: L2 Block Production

Mar 26, 20:25:00 GMT+0
Identified - The unsafe head on Unichain Sepolia stopped due to infrastructure issues. It is now advancing again..

Mar 26, 20:38:28 GMT+0
Resolved - This incident has been resolved..

]]> tag:status.unichain.org,2005:Maintenance/cm8ghp6e900flvfxds1yenx0w 2025-03-20T15:45:00.000+00:00 2025-03-20T15:45:00.000+00:00 Unichain Sepolia Pectra Blob Schedule Network Upgrade Type: Maintenance

Duration: 33 minutes

Affected Components: Node Syncing

Mar 20, 15:45:00 GMT+0
Identified - The Pectra Blob Schedule network upgrade is scheduled for Thu Mar 20 16:00:00 UTC 2025\. Node operators must have updated their nodes by this time. See <https://docs.unichain.org/docs/updates#critical-upgrade-for-unichain-sepolia-nodes-03152025> for more information..

Mar 20, 16:18:11 GMT+0
Completed - Maintenance has completed successfully..

Mar 20, 15:45:01 GMT+0
Identified - Maintenance is now in progress.

]]> tag:status.unichain.org,2005:Incident/cm8f8g33l0050tm4jlgzmekxf 2025-03-19T01:17:28.288+00:00 2025-03-19T01:17:28.288+00:00 Investigating Unichain Sepolia Batching Issues Type: Incident

Affected Components: L2 Block Production, Public RPC, L1 Batch Posting, Node Syncing

Mar 19, 01:17:28 GMT+0
Resolved - All rollup nodes are recovered, L2 block production continues and L1 batch posts are going through..

]]> tag:status.unichain.org,2005:Maintenance/cm850r9yu000110keqsge7trv 2025-03-11T21:42:51.504+00:00 2025-03-11T21:42:51.504+00:00 Mainnet Rollup Node upgrade Type: Maintenance

Affected Components: Public RPC

Mar 11, 21:42:51 GMT+0
Completed - We are upgrading our mainnet nodes to support Pectra.

]]> tag:status.unichain.org,2005:Incident/cm7z9nfb4000oima88s2r52g3 2025-03-07T21:00:00.000+00:00 2025-03-07T21:00:00.000+00:00 Public RPC Experiencing High Error Rate Type: Incident

Duration: 27 minutes

Affected Components: Public RPC

Mar 7, 21:00:00 GMT+0
Investigating - We are currently investigating this incident..

Mar 7, 21:26:53 GMT+0
Resolved - This incident has been resolved..

]]> tag:status.unichain.org,2005:Incident/cm7w04n340031k4oct3uj406d 2025-03-05T14:16:59.897+00:00 2025-03-05T14:46:03.264+00:00 Sepolia Unichain L2 blocks not being produced by sequencer Type: Incident

Duration: 29 minutes

Affected Components: L2 Block Production, Public RPC

Mar 5, 14:46:03 GMT+0
Resolved - This incident has been resolved..

Mar 5, 14:16:59 GMT+0
Investigating - We are currently investigating this incident. Transactions are not posting. .

]]> tag:status.unichain.org,2005:Incident/cm7vx44sf001flq263e08rli7 2025-03-05T12:52:37.725+00:00 2025-03-05T14:45:25.929+00:00 Sepolia Safe Head Rate Stalled Type: Incident

Duration: 1 hour and 53 minutes

Affected Components: L2 Block Production, Public RPC, L1 Batch Posting, Node Syncing

Mar 5, 14:45:25 GMT+0
Resolved - This incident has been resolved..

Mar 5, 12:52:37 GMT+0
Investigating - The Sepolia Unichain Batcher has stalled because of the Pectra hardfork. We are investigating..

Mar 5, 13:22:49 GMT+0
Identified - The L1 Pectra release has introduced a problem with deposit transactions and no transactions are going through L1\. We are waiting for L1 RPC partners to update to the new version geth/op-geth: <https://github.com/ethereum/go-ethereum/releases/tag/v1.15.5>.

]]> tag:status.unichain.org,2005:Incident/cm7tnk64p004frrgl8rlrjhtq 2025-03-03T22:20:00.000+00:00 2025-03-03T22:50:39.128+00:00 Sepolia: Safe Head Stall Type: Incident

Duration: 31 minutes

Affected Components: L2 Block Production, Public RPC, L1 Batch Posting, Node Syncing

Mar 3, 22:50:39 GMT+0
Resolved - This incident has been resolved..

Mar 3, 22:20:00 GMT+0
Identified - A scheduled maintenance led to an unexpected outage in our active sequencer for Unichain Sepolia. As a result the safe head being stalled until we were able to triage it..

]]> tag:status.unichain.org,2005:Maintenance/cm7memnh6000111gt5uybv98d 2025-02-26T21:03:50.235+00:00 2025-02-26T21:03:50.235+00:00 Scheduled Maintenance for Pectra release Type: Maintenance

Affected Components: L2 Block Production, Public RPC

Feb 26, 21:03:50 GMT+0
Completed - We are planning for a scheduled maintenance during this time. Expect transactions to be slow on chain for this period..

]]> tag:status.unichain.org,2005:Incident/cm7lboqke00kz13sb46y2yrn1 2025-02-26T00:53:00.000+00:00 2025-02-26T00:53:00.000+00:00 Transactions not being processed Type: Incident

Affected Components: Public RPC

Feb 26, 00:53:00 GMT+0
Resolved - A peering issue between the sequencer and ingress nodes caused a temporary period where no transactions or deposits were processed on Unichain Sepolia..

]]> tag:status.unichain.org,2005:Incident/cm5bcjduy001a2l0soosugdtx 2024-12-30T15:33:00.000+00:00 2024-12-30T15:33:00.000+00:00 No new blocks produced by sequencer Type: Incident

Duration: 4 hours and 10 minutes

Affected Components: L2 Block Production, Public RPC, L1 Batch Posting, Node Syncing

Dec 30, 15:33:00 GMT+0
Identified - A sequencer stall has led to the sequencer needing to resync from an earlier snapshot of the chain. This has led to no new blocks being produced while the sequencers catch up..

Dec 30, 19:42:59 GMT+0
Resolved - The sequencer has recovered and is producing new blocks..

]]> tag:status.unichain.org,2005:Incident/cm59woivt002eojkulcdt9rlw 2024-12-29T05:00:00.000+00:00 2024-12-29T17:00:00.000+00:00 Unichain Sepolia Safe Head Stall Type: Incident

Duration: 30 days

Affected Components: L1 Batch Posting, Node Syncing

Dec 29, 17:00:00 GMT+0
Resolved - This incident has been resolved..

Dec 29, 05:00:00 GMT+0
Identified - The op-node rejected some batches from the batcher and the safe head stalled out for 12 hours. Consequently, a re-org occurred. The batcher is correctly posting again..

]]> tag:status.unichain.org,2005:Incident/cm47ln3vv00147ipnyqgfanqg 2024-12-02T22:25:52.441+00:00 2024-12-02T22:25:52.441+00:00 Node Syncing Outage Type: Incident

Affected Components: Node Syncing

Dec 2, 22:25:52 GMT+0
Resolved - Due to an issue with the batcher, there was a deep reorg. Unichain Sepolia has recovered at this time. Users who are running full (non-archive) nodes will need to re-sync the chain..

]]> tag:status.unichain.org,2005:Incident/cm478l6qg004cpa98khiodtyl 2024-12-02T08:00:00.000+00:00 2024-12-02T19:28:28.028+00:00 Active Sequencer stalled Type: Incident

Duration: 11 hours and 28 minutes

Affected Components: Public RPC, L2 Block Production, L1 Batch Posting

Dec 2, 19:28:28 GMT+0
Resolved - This incident has been resolved. Batcher operation is restored, L2 blocks are being produced and safe head latency is at normal rates..

Dec 2, 08:00:00 GMT+0
Identified - At 12:00 AM PST, our active sequencer stalled and failed to derive or produce any further blocks. We have identified the issue as being related to the communication between op-geth and op-node over the Auth RPC port. We have mitigated this issue by restarted the sequencing nodes..

]]> tag:status.unichain.org,2005:Maintenance/cm3t7na36005qpfgn6hqfiehl 2024-11-25T18:00:00.000+00:00 2024-11-25T18:00:00.000+00:00 Unichain Sepolia Public RPC Maintence Type: Maintenance

Duration: 10 minutes

Affected Components: Public RPC, L2 Block Production, L1 Batch Posting

Nov 25, 18:00:00 GMT+0
Identified - We are planning for a scheduled maintenance during that time which will affect the public RPC and sequencer URL..

Nov 25, 18:07:13 GMT+0
Completed - Public RPC maintenance is complete & the RPC is functioning again..

Nov 25, 18:00:00 GMT+0
Identified - Maintenance has been started..

]]>