Troubleshooting Errors

Issues on the Exchange

INSUFFICIENT_OUTPUT_AMOUNT

The transaction cannot succeed due to the error: FusionXRouter:INSUFFICIENT_OUTPUT_AMOUNT. This is probably an issue with one of the tokens you are swapping.

You're trying to swap tokens, but your slippage tolerance is too low or liquidity is too low.

Solution

1. Refresh your page and try again later.

2. Try trading a smaller amount at one time.

3. Increase your slippage tolerance:

   1. Tap the settings icon on the liquidity page.

   2. Increase your slippage tolerance a little and try again.

4. Lastly, try inputting an amount with fewer decimal places.

Reason

This usually happens when trading tokens with low liquidity.

That means there isn't enough of one of the tokens you're trying to swap in the Liquidity Pool: it's probably a small-cap token that few people are trading.

However, there's also the chance that you're trying to trade a scam token which cannot be sold. In this case, FusionX Finance isn't able to block a token or return funds.

INSUFFICIENT_A_AMOUNT or INSUFFICIENT_B_AMOUNT

Fail with error 'FusionXRouter: INSUFFICIENT_A_AMOUNT' or Fail with error 'FusionXRouter: INSUFFICIENT_B_AMOUNT'

You're trying to add/remove liquidity from a liquidity pool (LP), but there isn't enough of one of the two tokens in the pair.

Solution

Refresh your page and try again, or try again later.

Still doesn't work?

1. Tap the settings icon on the liquidity page.

2. Increase your slippage tolerance a little and try again.

Reason

The error is caused by trying to add or remove liquidity for a liquidity pool (LP) with an insufficient amount of token A or token B (one of the tokens in the pair).

It might be the case that prices are updating too fast when and your slippage tolerance is too low.

Transaction cannot succeed

Try trading a smaller amount, or increase slippage tolerance via the settings icon and try again. This is caused by low liquidity.

Price Impact too High

Try trading a smaller amount, or increase slippage tolerance via the settings icon and try again. This is caused by low liquidity.

EstimateGas failed

This transaction would fail. Please contact support

Solution

If you got this error while removing liquidity from a MNT pair:

Please select "Receive MNT" and retry.

If you got this error while trying to swap:

Please contact the project team of the token you're trying to swap.** **This issue must be resolved by the project team.

Reason

This issue (while swapping) is caused by tokens which have hard-coded the V1 FusionX into their contract.

While this practice is ill-advised at best, the reason for these projects having done this appears to be due to their tokenomics, in which each purchase sends a % of the token to LPs.

The projects affected will likely not work with the V2 router: they will most likely need to create new versions of their tokens pointing to our new router address, and migrate any existing token holders to their new token.

We recommend that any projects which created such tokens should also make efforts to prevent their users from adding them to V2 LP.

Cannot read property 'toHexString' of undefined

"Unknown error: "Cannot read property 'toHexString' of undefined"

Solution

1. Check to make sure you have sufficient funds available.

2. Ensure you have given the contract allowance to spend the amount of funds you're attempting to trade with.

Reason

This error happens when trading tokens with insufficient allowance, or when a wallet has insufficient funds.

Out of Gas error

Warning! Error encountered during contract execution [out of gas]

You have set a low gas limit when trying to make a transaction.

Solution

Try manually increasing the gas limit (not gas price!) in your wallet before signing the transaction.

A limit of 200000 is usually enough.

The above example is from Metamask; check your wallet's documentation if you aren't sure how to adjust the gas limit.

Reason

Basically, your wallet (Metamask, Trust Wallet, etc.) can't finish what it's trying to do.

Your wallet estimates that the gas limit is too low, so the function call runs out of gas before the function call is finished.

ERC20: transfer amount exceeds allowance

Fail with error 'ERC20: transfer amount exceeds allowance'

Solution

1. Use Unrekt.net to revoke approval for the smart contract you're trying to interact with

2. Approve the contract again, without setting a limit on spend allowance

3. Try interacting with the contract again.

Reason

This happens when you set a limit on your spend allowance when you first approved the contract, then try to swap more than the limit.

ERC20: transfer amount exceeds balance

Fail with error 'ERC20: transfer amount exceeds balance'

You're probably trying to unstake from a Pool with low rewards in it. Solution below.

If not, you may be trying to send tokens that you don't have in your wallet (for example, trying to send a token that is already assigned to a pending transaction). In this case, just make sure you have the tokens you're trying to use.

First Tab

Firstly, let the team know which pool you're trying to unstake from, so they can top up the rewards. If you're in a hurry to unstake and you don't mind losing your pending yield, try an emergencyWithdraw:

You can perform an “emergencyWithdraw” from the contract directly to unstake your staked tokens.

1. Find the contract address of the Pool you're trying to unstake from. You can find it in your wallet's transaction log.

2. Go to https://explorer.mantle.xyz/ and in the search bar, enter the contract address.

3. Select Write Contract.

4. Click “Connect to Web3” and connect your wallet.
5. In section “4. emergencyWithdraw”, enter "0" and click “Write”.

This will unstake your staked tokens and lose any uncollected yield.

This will lose any yield that you haven’t harvested yet.

Second Tab

This error tends to appear when you're trying to unstake from an old Single Staking Pool, but there aren't enough rewards in the pool left for you to harvest when withdrawing. This causes the transaction to fail.

Unsupported Chain ID

Switch your network to Mantle Network. Check your wallet's documentation for a guide if you need help.

Internal JSON-RPC errors

"MetaMask - RPC Error: Internal JSON-RPC error. estimateGas failed removeLiquidityETHWithPermitSupportingFeeOnTransferTokens estimateGas failed removeLiquidityETHWithPermit "

Happens when trying to remove liquidity on some tokens via Metamask. Root cause is still unknown. Try using an alternative wallet.

Internal JSON-RPC error. { "code": -32000, "message": "insufficient funds for transfer" } - Please try again.

You don't have enough MNT to pay for the transaction fees. You need more ERC-20 network MNT in your wallet.

Error: [ethjs-query]

Error: [ethjs-query] while formatting outputs from RPC '{"value":{"code":-32603,"data":{"code":-32000,"message":"transaction underpriced"}}}"

Increase the gas limit for the transaction in your wallet. Check your wallet's documentation to learn how to increase gas limit.

Swap failed: Error: [ethjs-query] while formatting outputs from RPC '{"value":{"code":-32603,"data":{"code":-32603,"message":"handle request error"}}}'

Cause unclear. Try these steps before trying again:

1. Increase gas limit

2. Increase slippage

3. Clear cache

Checking username keeps spinning

There are two possible causes.

1. You have multiple wallets installed on the browser.

2. Network issue.

Solution 1

Root cause: You have multiple wallets installed on the browser. It may make a conflict between wallets. This is out of FusionX Finance's control and we can do nothing.

1. Have only single wallet installed on browser, remove the others.

2. Reconnect the wallet and retry setting username again.

Second Tab

Root cause: Network is unstable.

You have to retry.

1. Delete whatever has been entered in the text field completely.

2. Re-type username, then please wait for seconds.

3. If it doesn’t work, reload the page and retry again.