Thank you for your suggestion.
I have looked for BizAgiPMSetup via the Internet, but the earliest version I could find was 2.3.
I have sent an email to Bizagi to ask whether they would provide a link to v2.1, and I am hopeful they will respond.
I have found just one Designer for XPDL 2.1, namely the Yaoqiang XPDL Editor v2.1.21 from SourceForge.
But alas QC refuses to load it.
I wonder if you have a small XPDL file you know is loaded by QC, so I can eliminate whether there is a QC fault.
Thanks
John