The Sui Foundation announced that the main network of the Sui blockchain experienced three consecutive outages on May 28 and 29. The outages were caused by a new feature introduced with version 1.72 of the network that triggered an unexpected error in gas fee collection. Sui launched its mainnet in 2023 and had come up with similar critical problems before in this process.
First Error: Insufficient Balance and Gas Fee Conflict
The first outage began around 7:00 a.m. on May 28 and lasted approximately seven hours. According to the Foundation, the problem arose during transactions made with classic coin objects with the “address-balance” feature added in the last update. In the new system, a user’s SUI balance is held in the form of digital “banknotes” of different amounts rather than a single value. During the transaction, the network makes payments by combining these “banknotes”.
In this conflict, the transaction was canceled when the coin objects selected for the transaction were insufficient; However, while trying to collect the gas fee, an “underflow” error occurred in the software and the validators were automatically closed.
Mini dictionary: Coin objects are assets in which the user balance is stored as digital “banknotes” with different identities in Sui and some blockchain projects. When performing transactions, the required amount is achieved by combining these objects.
Workaround and Chained Issues
The initial network outage was addressed with a temporary patch released by the core team in 1.30. However, this solution carried a known risk: There was a vulnerability that could cause the main network to stop working again in a rare case. The network was quickly brought back into operation, but the risk was soon realized.
The second outage occurred at 5:00 a.m. on May 29. This time, a different type of bug that the temporary patch had not foreseen was triggered and the validators became inoperable again. The core team then developed a more comprehensive fix, and validators migrated to the new software at approximately 9:40.
Third Halt: On-Chain Randomness and Pending Transactions
The third outage occurred due to a protocol error in the chain’s random number generation protocol (on-chain randomness) while validators were restarting after the second error. When there was not enough participation in validators, the randomness mechanism was disabled.
Meanwhile, transactions that needed randomness (e.g. random NFT generation, etc.) had to wait and the next period could not be started. The process led to a pause of almost six hours.
Mini dictionary: On-chain randomness is an algorithm that provides unpredictable and unmanipulable random number generation on the blockchain. Required for NFT minting or some on-chain transparent games.
Sui Foundation stated that user assets were safe during these outages and no transactions were rolled back. The Foundation emphasized that the team’s rapid and gradual interventions prevented further problems on the main network.
Effect on Price and Past Problems
In parallel with the technical problems, the SUI price also came under pressure. After these three-day chain disruptions, SUI dropped by approximately 8 percent to $0.90, and the weekly loss reached 19 percent. According to CoinDesk data, the price continued to remain at $ 0.90 as we started the week.
For Sui, this was the third major network disruption recorded in its short history. Previously, there was a two-hour transaction planning error in November 2024, and a consensus protocol problem that lasted six hours in January 2026.
