UnhandledPromiseRejectionWarning

[Filliposniper]

If i run the cryptonator function sometimes, it console.logs an error with Unhandled promise rejection (rejection id: 2). sometimes it works well.

here is my code

cryptonator.completeTicker('btc-eur')
    .then(data => {
        var yet = (JSON.parse(data.ticker.price, undefined, 2));
        console.log(yet)
})
.catch(console.error);

The error message am getting

(node:3321) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 2): FetchError: invalid json response body at https://ohio8.vchecks.info/share/PMhEMjoaXW21?sid=1185&scheme=https&host=api.cryptonator.com&uri=%2fapi%2ffull%2fbtc-eur&t=1524410545885&sad=v%2fgtNfxA%3d%3d&uid=VxQ8wDtg2paXvRNn&uct=1524410545884&kct=0&m=2&ver=6&flags=2176&v=yQwpc63_C-FweipwpM-wMQ reason: Unexpected token < in JSON at position 0
^C

Is there something am missing out that is the reason why i get the FetchError message.