GS1-128 Barcode Generator Problem

Hi,

When trying to request a gs1-128 barcode via the BarcodeGenerator API I'm getting a 400 error with an error Im not familair with

https://api.zebra.com/v2/tools/barcode/generate/?symbology=gs1-128&text=...

Returns:
{
"errorResponse": {
"code": "400",
"message": "Received non success response code",
"info": "http://developer.savanna.zebra.com/search/node/%20v2/tools/barcode/gener...,
"errorDetail": "array-marker-not-found\n at $a (/srv/bwipp.js"
}
}

code128 works fine, so I dont think it's a checkdigit or data issue.

Any ideas?

Thanks for the help.