Some more detail for the community:
the issue is in the files_source_ script. We will be correcting this and merging this to dev soon.
In the meanwhile, if you do a migration before we complete this OR if you've done a migration, you should check to see the current state of your installation.
Run the following select script:
SELECT count(*) FROM datafilecategory where dataset_id in (SELECT id FROM dvobject where dtype='DataFile');
If it returns anything other than 0, then run the follwoing update script*:
update datafilecategory set dataset_id=dvo.owner_id
from dvobject dvo
* technically you can run the update without the select, it's just good practice to get the number from the select, then run the update in a transaction and confirm the same number of rows are updated.
Thanks, and please let me know if you have any questions about this,