A bug in the Arbitrum blockchain’s software caused the network to stop processing transactions on the chain for a period of time. According to the official Twitter account of Arbitrum developers, this was due to a bug in Arbitrum’s sequencer. The sequencer is responsible for receiving user transactions, creating transaction batches, and publishing them to the Ethereum chain.
The software bug caused a large backlog of transactions that were not posted to the chain, putting pressure on the network, eli_defi, community lead at the Arbitrum Foundation, wrote on Discord. "A fix was deployed earlier today and everything is currently operating as expected."