I'm having issues claiming lumens as it keeps saying it doesn't recognize BTC address. I get this message --> "Can't find this Bitcoin address. Make sure it's valid and had a positive balance at first block on June 26, 2017. Please try again."

My BTC's are on a nano s and a keep key. I'm just putting in my public BTC address.. What step am I missing?

-- Bitcoins have been in cold storage for long time, so these aren't anything I transferred after the chain snapshot was taken on the 26th.

Thanks,

Craig