There are usually three reasons why transactions have been pending and cannot be packaged by the network.
The Nonce of the transaction is not the next Nonce that should be packaged
The gas price of the transaction is 0
Insufficient gas limit for transaction
You can check which problem you are experiencing according to the following steps
Open https://scan.genechain.io and enter your address in the query box in the upper right corner to view your transaction history
Find the latest transaction you sent, and click the transaction hash to view the details of this transaction. Please note: Make sure that the number 1 in the figure is your account address, because transactions sent to you by other people will also appear here. Then click 2 in the figure to query the transaction details
Record the Nonce value of this transaction, assuming it is
N, the Nonce value of the next packaged transaction can only be greater than this value by 1
Open MetaMask to query transaction history, MetaMask desktop can click on the activity to view transactions in the queue, MetaMask mobile needs to click on the transaction history in the menu.
Click on the top transaction in MetaMask, which is usually the first transaction blocked
Check the Nonce value of this transaction, suppose it is
If the Nonce of blocked transaction (M) and the Nonce of last packaged transaction (N) are not continuous, that is,
M≠N+1, you need to custom the nonce of reset the Nonce and resend the transaction with Nonce as
If Nonce is continuous, that is,
M=N+1, you need to continue to check Gas Price and Gas Limit
It is recommended to check the Gas Price (fuel price) first. When Gas Price is 0, it will not be packaged by the network. Please refer to Speed Up or Cancel the transaction and increase the Gas Price to allow the network to package this transaction.
If the Gas Price is not 0, the usual cause is that the Gas Limit is too low, making the network unable to package transactions. Please refer to Speed Up or Cancel the transaction, increase the Gas Limit and increase the Gas Price at the same time to allow the network to package this transaction.
Speed Up or
Cancel button under the pending transaction
Advanced to increase Gas Price (increase by 1 each time) and Gas Limit (increase by more than 0.5 times each time) when accelerating or canceling, try to allow the network to pack this transaction normally. Note: You can click to speed up and cancel on MetaMask mobile, but you cannot customize the Gas Price during acceleration or cancellation, so it is very likely to be unsuccessful. At this time, it is recommended to custom the nonce and resend the transaction.
You can turn on Custom Nonce in the settings to fill in the Nonce of a transaction manually as following.
After turning on the switch of the custom transaction Nonce, you can fill in the required Nonce when sending the transaction. Fill in the next Nonce when sending a new transaction. Remember to increase the Gas Price (needs to be higher than the pending transaction with the same nonce by at least 1, otherwise you will encounter the
replacement transaction underpriced error) and Gas Limit (it is recommended to increase by more than 0.5 times, otherwise you may encounter the same pending problem)
If you cannot speed up or cancel or still cannot get packaged, in this case, you need to click
Reset Account in
Settings -> Advanced to reset the random number. This action will reset your random number and clear your transaction history, but will not change the balance in your account or require you to re-enter the mnemonic phrase.
After resetting the nonce value, you can resend the transaction covering the same nonce transaction that is queued on the network. At this time, please remember to increase the gas price to cover the transaction queued on the network to avoid the gas price of the new transaction not being higher than the old transaction which will lead to REPLACEMENT_UNDERPRICED error and cannot overwrite the old transaction.
If you are using MetaMask mobile and encounter the problem that resetting the nonce does not work, it is recommended to try the desktop version or reinstall MetaMask mobile. But DO REMEMBER to save your private key or mnemonic phrase in advance.
If you encounter a CALL_EXCEPTION error after increasing the Gas Price or not, it is usually because MetaMask estimates the Gas Limit lower than the actual gas required. In this case, increasing gas limit might help.