Terra Classic Core v4.1.1 Upgrade Nears: Why It Matters for LUNC

Terra Classic is approaching an important network upgrade designed to fix a transaction problem that previously left an account unable to send further transactions. The Terra Classic Core v4.1.1 upgrade is expected around October 26, 2026, at approximately 15:00 UTC, marking another step toward improving the network’s reliability.

The upgrade addresses a problem known as a stuck transaction, which can prevent subsequent transactions from the same account from being processed. It also includes fixes for tax related errors and restores the ability to use certain accounts with vesting schedules.

For LUNC holders, the key point is that this upgrade focuses on network reliability and account functionality. It does not introduce new modules, change network parameters, or alter existing balances, transaction fees, or tax settings.

Why Is Terra Classic Upgrading to Core v4.1.1?

The main reason for the upgrade is to prevent transactions from becoming permanently stuck under certain conditions.

Normally, when someone sends a transaction on Terra Classic, it waits to be processed by validators before being included in a block. However, a bug in the network’s transaction handling process could cause a transaction to remain pending indefinitely.

When this happened, the affected account could not successfully send additional transactions because the network processes transactions from each account in a specific order.

The issue was experienced on Terra Classic mainnet by a validator whose operations were affected. The validator could not complete the transaction needed to leave jail for an extended period and required a manual recovery process.

Terra Classic Core v4.1.1 is designed to eliminate the underlying cause and introduce an additional safeguard to prevent similar problems from leaving accounts blocked.

This makes the upgrade important because reliable transaction processing is essential for users, validators, decentralized applications, and other services operating on the network.

What Problems Does the Upgrade Fix?

The v4.1.1 upgrade includes four main functional improvements.

1. Prevents Transactions From Getting Permanently Stuck

The most important change addresses the transaction problem that can prevent an account from sending further transactions.

Under the previous system, a transaction could remain in the network’s pending transaction queue even after it had been removed from the list used to build blocks. As a result, validators continued passing the transaction between nodes without including it in a block or properly dropping it.

The new version fixes the cause of this mismatch and adds a safeguard to keep pending transaction records consistent.

If a transaction is dropped, it can be submitted again instead of permanently blocking the account’s subsequent transactions.

2. Improves Tax Module Reliability

The upgrade includes two fixes designed to prevent errors in Terra Classic’s tax module.

These changes address situations in which certain missing settings or unusual tax parameter combinations could trigger software errors.

The fixes are intended to make the tax module more resilient. They do not change the current mainnet tax calculation or its existing rounding behavior under normal parameter settings.

For LUNC users, this means the upgrade is focused on improving reliability rather than introducing a new tax system or changing the current transaction tax.

3. Restores Functionality for Certain Vesting Accounts

Another important fix concerns accounts with vesting schedules that were affected by an account reading problem.

Some of these accounts could not be properly accessed through certain account queries, and transactions signed by them could fail. This also affected the ability to move funds through those accounts.

Core v4.1.1 fixes the compatibility problem so the affected accounts can be read and used again after the new version is activated.

The issue did not mean the funds had been lost. Instead, the affected accounts were not functioning as intended.

4. Improves Overall Network Reliability

Together, these fixes are intended to reduce transaction processing failures and improve the reliability of important network functions.

The upgrade has been tested using a test network based on real Terra Classic mainnet state. Testing reproduced the stuck transaction problem before the upgrade and confirmed that the problem no longer occurred in the tested scenario afterward.

The testing also included checks of bank transfers, staking operations, and CosmWasm smart contract functions.

These results provide evidence supporting the fixes, although they do not mean that every possible software issue has been eliminated.

What Will Change for LUNC Holders After the Upgrade?

For ordinary users, the upgrade is not expected to introduce major changes to how they use Terra Classic.

Here is what users should know:

• No change to balances: The upgrade does not include a state migration that changes existing account balances.
• No change to transaction taxes: The current tax settings are not being changed by this upgrade.
• No change to transaction fees: The upgrade does not introduce a new fee structure.
• Improved transaction handling: Transactions should no longer become permanently stuck through the specific issue addressed by the upgrade.
• Restored vesting account functionality: Affected vesting accounts should become readable and usable again once the new software is active.

LUNC holders do not need to manually upgrade their wallets or transfer their tokens because of this software update. The upgrade is primarily a responsibility for validators and node operators.

However, users should be aware that the network is expected to pause briefly at the scheduled upgrade height while validators switch to the new version.

Why Must Validators Upgrade at the Same Time?

Terra Classic Core v4.1.1 requires a coordinated network upgrade rather than allowing validators to update whenever they choose.

This is because the new version changes how certain block proposals are handled and allows transactions from affected vesting accounts to succeed where they previously failed.

If validators running different versions disagree on whether a block proposal or transaction is valid, the network could experience consensus problems.

For that reason, validators must activate the new version at the designated upgrade height.

According to the published upgrade instructions, the network will halt at block height 31,010,600. It will resume once validators representing more than two thirds of the network’s voting power are running the new software.

Exchanges and infrastructure providers must also ensure their nodes are compatible with the upgrade to continue operating and syncing with the network.

When Is the Terra Classic Core v4.1.1 Upgrade?

The upgrade is scheduled for approximately October 26, 2026, at 15:00 UTC, at block height 31,010,600.

The timeline is an estimate, and the exact timing may change depending on block production and network conditions.

Validators and node operators are instructed to continue running version 4.0.2 until the designated upgrade height rather than switching to v4.1.1 early.

Users can monitor official Terra Classic governance and development channels for updates regarding the final upgrade schedule and network status.

What Does This Upgrade Mean for Terra Classic?

The Terra Classic Core v4.1.1 upgrade is primarily a reliability and maintenance update rather than a major feature release.

Its importance lies in addressing a real transaction processing problem, adding safeguards against similar failures, improving tax module resilience, and restoring functionality for certain vesting accounts.

For LUNC holders, the expected impact is straightforward: existing balances, transaction taxes, and fee settings remain unchanged, while the network gains fixes intended to make transactions and account operations more reliable.

The upgrade is not a direct change to LUNC tokenomics or a guarantee of price movement. Instead, it addresses underlying software issues that matter to the continued operation of the Terra Classic blockchain.

As the scheduled upgrade approaches, attention will turn to its successful activation and the network’s ability to resume normal operations afterward.