Some masternode operators have experienced errors or UI issues when trying to claim rewards via https://masternodes.swarm.fund/
In this case, follow these simple instructions for claiming Masternode Rewards manually:
Connect to the smart contract using Metamask with your associated staking wallet by clicking "Connect to Web3".
Look for the "collect" function (number 11) and click Write.
Sign the transaction. You will receive all due rewards when the transaction is verified.
After 30 confirmations, the payout will be reflected in the Masternode Dashboard.