What command did you do? also depending on what node you are connected to and if the plugin is enabled then certain commands won't work. You would also need to import the private keys of the accounts you are looking to list their balance. If you do have the keys imported to your Cli_Wallet, you can do list_my_accounts. I know this node wss://gtg.steem.house:8090 has the plugin enabled. You can also use get_account STEEMUSERNAME and get them individually...