This article describes how to troubleshoot UNKNOWN_ERROR (0x650f) which might trigger when connecting a Ledger device to MetaMask.
Troubleshooting
- Close Ledger Live.
- In MetaMask, go to Settings > Advanced, scroll down to Preferred Ledger Connection Type, and select WebHID.
- Make sure that your Ledger device is unlocked and not on screen saver.
- Open the Ethereum (ETH) app on your Ledger device by navigating to the Ethereum icon and pressing both buttons simultaneously.
Your device displays: Application is ready. - In MetaMask, go to Settings > Connect Hardware Wallet, select Ledger and click Continue to attempt the connection again.