I’m trying to figure out this same issue. I would like to display the SalePrice, which seems to be available in the XML response, but I can’t find where this is being handled by the library.
I’m getting this error also. It happened just after downloading and then pressing the activate button. Activation was possible from the plugin page, but the editor only seems to be showing up in the theme editor… which is not a problem, but it would be neat to also get it in the page and post edit views.
