Error: Call to a member function getData() on null after trying to import

Hi,

Actually my dream was to export all my papers from (abandoned?) OCS to OJS (Is OCS still secure? Or: how can I migrate OCS to OJS? - #2 by alantygel). Since the first experiments on doing this shows that both XML schemas area completely different, I started from the begging doing a supposedly very simple test: export and import the very same article from the very same OJS instance back to itself.

And this was how I end up in this situation.

thanks for the attention, best regards.
alan