Unable to create an artifact using Client extension API

 I'm currently looking into developing an opensocial gadget widget extension for IBM Engineering Requirements Management DOORS Next. The Problem is that I'm able to create a new Artifact following the documentation here: https://jazz.net/wiki/bin/view/Main/RMExtensionsAPI6061#CreateArtifact in Version 6.0.6.1, but the same Code does not work for Version 7.0.2. The Documenation for 7.0.2 is the same: https://jazz.net/wiki/bin/view/Main/RMExtensionsAPI702#CreateArtifact . The error I get is: can't read value of undefined, although everything is the same as in 6.0.6.1.