Steps to reproduce:
1. Copy the attached file org.opencastproject.ui.metadata.CatalogUIAdapterFactory-series-bug.cfg into your etc folder.
2. Notice the file defines an XML namespace with an empty prefix assigned
3. In the Admin UI, create a new series
4. In the tab "Metadata II" of the wizard, write any random value in the parameter defined
After saving the series, its metadata cannot be read anymore. The logs show huge XML parsing errors. The generated series catalog that can be found in the table "mh_series_elements" is malformed (the root element contains an "xmlns:" attribute --notice the trailing colon--).
An extra XML catalog should be generated. The element should have an empty prefix, which is allowed in XML.
Workaround (if any):
Even though the steps to reproduce this bug are specifically related with the definition of extra metadata catalogs in the UI, the underlying cause is in a lower level, at the XML catalog implementation used in Opencast.