Block production on Avalanche appeared to stall on Wednesday after some nodes failed to verify transactions.

According to data from Avalanche block explorer Snowtrace, no new blocks were added to the Avalanche C-Chain for two hours on Wednesday evening, leading some blockchain users to the conclusion that there was an outage on the network.

Ava Labs’ Head of Communications Patrick Sutton clarified that while the network had slowed down earlier, Snowtrace was updating at an even more delayed pace.

Avalanche co-founder Kevin Sekniqi said in a tweet that the network had been “unstable for a bit over an hour,” owing to a bug with version 1.9.12.

The bug in question caused some nodes to fail when verifying transactions while boostrapping, which refers to the process of downloading linear chain blocks to recreate the latest state of the blockchain. 

The network was restored shortly after developers issued a fix in the v1.9.14 update and stabilized as validators began to upgrade their nodes.

“If you upgraded to 1.9.12 you were fine, but if you were still sticking to 1.9.11 and earlier, you stopped agreeing on an x-chain transaction with all other 1.9.12 nodes due to a check bug, so there wasn’t agreement, and therefore progress. It was safe, but not live,” explained Sekniqi.

The issues with the network led to some parties suspending functions related to Avalanche. Korean crypto exchanges Upbit and Bithumb halted AVAX deposits and withdrawals. Cross-chain decentralized exchange (DEX) ThorSwap also announced a temporary halt for AVAX on THORChain until all nodes had adopted the emergency fix.