Manually adding new release through https://beta.musicbrainz.org/release/add or seeding any release to https://beta.musicbrainz.org/release/add it is unable to submit any edits because of:

Some errors were detected in the data you’ve entered. Click on the tabs shaded red and correct any visible errors.

However I don't observe any errors.  I tried various modifications to the seeded data, but still couldn't get past the false errors:

• I tried deleting fields where an empty string was being seeded.
• I tried deleting all seeded URL relationships

Seeding to https://musicbrainz.org/release/add without any changes to the data still allows the edits to be submitted.