You may encounter the error "Not supported" when trying to sign an extrinsic with your Ledger via the Polkadot-JS UI or the Polkadot extension

This error means that the specific extrinsic is not supported by the Ledger app. You can find the list of supported extrinsics for Polkadot here and for Kusama here.

You'll probably notice that there are two versions: the "light" version and the "XL" version. Ledger Nano S users by default use the light version, because it has much smaller size, but it also supports a limited number of extrinsics. Ledger Nano X users use the XL version by default.

If you're using a Ledger Nano S, you can still use the XL version if you want, but odds are there won't be much space left for any other apps.

NOTE: Ledger Live natively supports only the light version for the Nano S. If you install the XL version you won't be able to use your Ledger Nano S with Ledger Live.

How to install the XL version

1. On Ledger Live, uninstall the existing version of the app. You can find instructions on Ledger's support page

2. Then go to Settings > Experimental features

3. Enable "Developer mode"

4. In Manager search for "Polkadot" and you should see these three versions:

5. Install the XL version

NOTE for Kusama users: If you are installing the Kusama XL version you can skip steps 2 and 3 above. All the versions are available by default.