I found the answer. One of your inputs has to be exactly 1000 CHC. If you go to the Send Tab, then "Inputs", you probably see just one input of 1001 CHC. You need to send a transaction to yourself by generating a new address (Click Receive tab and then "Request Payment") and send exactly 1000 CHC to your new address.

I tried that and now the "masternode outputs" command does give me TXID, and I was able to start the MN successfully.