InfoPath Dev

I have an application web service which just returns XML responses. In a browser, a URL like http://server:port/webservice/objects/list will return an XML list of the objects I want to use as a data source. The webservice does ask for basic http authentication (which in chrome can be done with http://user:password@server:port/webservice/objects/list). In InfoPath Designer 2013 I try to create a data connection to rest webservice using the same URL. It flashes a couple times, then gives two notices: "sorry we couldn't open [url]" and then "InfoPath cannot open the XML document: [url]. Not enough storage is available to process this command". It never asks for authentication so I doubt it's going where it's supposed to. I also tried to add a data connection From Other Sources > XML using the same link and got the same error. While googling, it seems like many people have had similar issues, but almost always with https or server-side issues or old versions of IE. None of these are the case for me. I get an event in event viewer as well every time I attempt to connect - attached screenshot, but it basically says the same thing.

Usually when I've seen this it is an authentication issue - but I don't know of a work around. Is this a REST or SOAP service?

This is a rest service. I'm just not sure how to pass any credentials if it doesn't prompt for them. As an aside - how do line breaks work on this forum?

Unfortunately, the forum runs on rather old software - if you use IE, you get better formatting. I'm going to ask a colleague of mine if he has any ideas on how to work around the credential issue - I'm wondering if perhaps you put them in your Windows credential manager? But then all your form users would need to do that.... I guess once you get a data connection created, you may be able to use UDCX with the credentials stored in it?