"Exporters now explicitly only understand strings. The provided registry handlers encode and decode data automatically to and from utf-8. Their default encoding changed from None to utf-8. If you have custom registry handlers, ensure that you encode your unicode. Check especially if you use a page template to generate xml. They return unicode and their output must also encoded. If you choose to encode your strings with utf-8, you can be sure that your code will also work with GenericSetup < 1.7"
So the existing code breaked the exporter. Maybe there's a way to fix it more elegantly, but this works.
As stated in the GS changelog:
"Exporters now explicitly only understand strings. The provided registry handlers encode and decode data automatically to and from utf-8. Their default encoding changed from None to utf-8. If you have custom registry handlers, ensure that you encode your unicode. Check especially if you use a page template to generate xml. They return unicode and their output must also encoded. If you choose to encode your strings with utf-8, you can be sure that your code will also work with GenericSetup < 1.7"
So the existing code breaked the exporter. Maybe there's a way to fix it more elegantly, but this works.