You may encounter the error "txn version not supported" when trying to send DOT or KSM from your Ledger via the Polkadot-JS UI or Ledger Live. 


This error is caused by outdated software. This happens because Polkadot and Kusama can upgrade themselves with a governance decision, but these upgrades sometimes change the way transactions are constructed in a way that is incompatible with previous versions. To fix this:


  • Make sure your Ledger's firmware is updated
  • Update your Ledger Live app to the latest version
  • Update your Polkadot or Kusama app to the latest version - depending on which network you are experiencing this error.


These steps didn't solve the issue


New Polkadot/Kusama app versions are now released before the new runtime upgrade happens. If the problem persists after these steps, it's possible that Ledger Live is failing to display a prompt to update. In some cases, there can be issues with seeing the correct version number for the app in Ledger Live. If this happens, you can manually install the new Ledger Live software here.