The Base layer-2 network experienced two outages last week due to a sequencer bug, according to a post-mortem published by the engineering team. The sequencer is a single component that orders transactions; a flaw in its block-building logic allowed stale journal state to remain after a failed transaction, halting block production. The first outage lasted 116 minutes and the second 20 minutes, during which no new layer-2 blocks were created. The sequencer and validator nodes could not advance past the invalid block until the issue was resolved. Engineers applied a patch to update the journal state correctly and addressed a race condition that delayed recovery; the team noted that infrastructure constraints extended the mitigation time. The team said it will increase fuzz testing and develop graceful recovery procedures so validator nodes can resume without manual restarts. This incident follows earlier sequencer outages in September 2024 and August 2025, and Base, which secures just under $11 billion in value, remains the second-largest layer-2 network. The post-mortem was released as part of Cointelegraph's independent reporting effort.