REST Resource Discovery gives malformed HTTP-request

When using the Schema Discovery wizard to fetch a Requirment Manager (rm) schema within JTS/Requirements Composer, the following error message appear when selecting the top XML node and the href as elment attribute and pressing next on the "Locate using Data Service"-wizard page:

CRRRE2861E: I/O error 'Server returned HTTP response code: 400 for URL:

The error indicates a malformed HTTP-request. How could it be when the request is automatically generated by the schema discovery wizard?

I am using RPE 1.1.2.2 and Requirements Composer 4.0.1.