Ledger does not support batch transactions. Therefore you will run into the "utility.batch error" when trying to perform certain actions on polkadot.js

1. Utility.batch error during Staking process

When you use your Ledger wallet to stake your DOT tokens, you will run into the error "utility.batch not supported" when choosing your validators. There is an easy fix for that: 

• Go to the "Staking" tab found under the "Network" dropdown in the top navigation menu.
• Click the "Account Actions" pane in the inner navigation.
• Click "+ Stash" instead of "+ Nominator" or "+ Validator" (selecting the latter two will not work).
• Input the amount of tokens to bond and confirm the transaction.
• Confirm the transaction on the Ledger devivce.
• When the transaction is included you will see the newly bonded account in the "Account Actions" page.
• Select "Start Nominating" or "Start Validating" to start nominating or validating.
• Confirm the transaction on Apps and on the Ledger device.

2. Utility.batch when requesting Staking rewards payouts

Note that you do NOT need to request payouts. They will be triggered by the validators approximately once every 24 hours. In theory anyone can trigger the payouts, but they would also have to pay the transaction fees for this transaction. Since this would trigger all payouts to all nominators - not just to you - this would be a batch transaction, which is not possible to perform with the Ledger. 

3. Utility.batch error when clearing expired democracy votes