I think it was a problem with the container's name I was trying to create. The container's name I tried was 'IT&Controlling'. It seemed to be that this '&' was the issue(VariableEditor didn't like it). I changed the name to 'ITAndControlling' and everything ran smooth.
I had this issue after updating to QlikView 11.20 SR13. I found in the release notes of QDF 1.5.1 that the Security Settings of QlikView 12 needed to be changed to allow it it work. This is also true in Qlkiview 11.20 SR13 where the default security settings prevent the Variable Editor from creating container objects. The User Preferences >> Security Tab needs the "Script" box checked