JSON body needs square brackets at either end.

[grantbruneau]

To get this to work I had to add the -AsArray property to the concerto-json command.

$JSON = Convertto-Json $request -AsArray

[paulzmuda]

Can confirm in linux bash version also now needing to be sent as an array:
request='[{"data":"'$currentIp'","ttl":3600}]'
It appears GoDaddy now requires request to be sent as an array of one object instead of a lone object.

[Taegost]

This was fixed with #4 for Windows, I can test out the change suggested by @paulzmuda later to see if that makes it work for Linux as well

[bmo-at]

Ran into this today and created a pull request #7, unfortunately without seeing this first; so that's 20 minutes of my life spent on the valuable lesson of looking at issues before doing debugging on your own