I am trying to send feeds using Amazon SP-API (roughly following this guide). When I format my feeds in XML, it works fine. But when I try to send a flat-file (tab-separated-values), I get a long XML error that boils down to:"XML Parsing Fatal Error at Line 1, Column 1: Content is not allowed in prolog. Content is not allowed in prolog".
This is an XML error, so basically Amazon processes my feed as an XML feed even though it's not even XML.
In the first API call of the process, createFeedDocument, there's a ContentType argument in which you send the format of your feed. I send:"text/tab-separated-values; charset=UTF-8" as ContentType, but Amazon seems to ignore it and treat it as XML anyway. I have tried literally dozens of variations of content type, but all of them lead to the same result - Amazon ignored whatever was in there and parsed it as XML anyway,I'm sure the flat file feed itself is in the correct format because it works fine in MWS - this is a problem since I migrated to SP-API.
Would greatly appreciate any help on this issue because I'm getting desperate. How do I send flat file feeds using SP-API and make Amazon realize it's a flat file?Thanks a lot!