what is the result for the request?
what do you set as a resultFormat for HTTPService?
default, I am not changing it.
What do you get throw this HTTPService? XML, file or something else?
I think the problem is that I am not getting what I need. But yeah I should get XML file.
If it should be xml, set resultFormat=xml or e4x for your HTTPService.
Also you can use debugger or sniffer to check what do you get.
This error is means that result has unknown format.