Why can't I ingest my object even though the FOXML seems to be valid?

If you get errors ingesting your FOXML such as messages reporting element namespace prefixes not being bound, you may be running into the issue reported in FCREPO-796.

The contents of inline XML datastreams need to be well-formed XML in their own right. Particularly if you are using any namespace prefixes these need to be declared within the inline datastream contents - specifying the namespace at the root element of the FOXML won't work.