If you are reading this article you have probably seen the error "Transaction rejected or failed" pop up in our Dashboard, we are here to help you resolve it.
This error appears when the Dashboard registers that an attempted transaction wasn't accepted by the network successfully.
If you didn't reject the transaction, it means one or more of the characteristics of the transaction are invalid.
You may have unresolved transactions in your wallet transaction history which were not cancelled. You should reset your Account in your wallet - in Metamask, this option falls under the Advanced Options within the Settings menu.
The RPC endpoint you're using might not have accepted the transaction. To change the RPC endpoint and try a different one, follow the instructions here
Metamask may be incorrectly estimating the gas price for your transaction. Check out the gas tracker page on Polygonscan to see an accurate estimation, then manually adjust your gas pricing in Metamask.
If that doesn't resolve the problem, then you may need to share additional logs with us via our support chat in the bottom right of your browser. To find the logs, please press Command + Option + J (Mac) or Control + Shift + J (Windows, Linux, Chrome OS). Any errors in Red created at the moment of your issue occurring will be useful to diagnose it.