Short version: Efforts to add a new release using the NGS workflow and a FreeDB import to populate the tracklist fail consistently and have to be abandoned. The point of breakage appears to be clicking on the radio button "Add disc" at the bottom right of the tracklist generated by the FreeDB lookup. Nothing happens and the entire process freezes at that point.

Long version: I have several decades experience breaking software, but zero formal IT training. I most frequently use Kubuntu with several browsers but did these tests with Windows 7 and Google Chrome. I also have a Mac box and can therefore test with a variety of OSs and browsers.

My process was:
1. CD Lookup from within Picard; CD not found
2. Lookup manually
3. Search by artist in default browser (Chrome)
4. Add new release
5. URL at this point was (from summary notes) ngs.musicbrainz.org/release/add
6. populated basic data in first frame "Release Info" and clicked on Continue
7. next screen was tracklist frame, confirming language and capitalization
8. clicked on "Add disc"
9. Selection box came up with four choices: Manual entry | Existing tracklist | CDstub import | FreeDB import
10. Selected FreeDB import; filled in details of title, artist and number of tracks of FreeDB listing and clicked Search
11. link to correct disc appeared, clicked on it, message "Generating tracklist" appeared
12. At bottom of long tracklist (29 tracks) were two radio buttons, "Cancel" on left and "Add disc" on right. Clicking on "Add disc" button did nothing.
13. Notes are unclear whether I clicked next on "Cancel" button on tracklist info box or on underlying tracklist frame. In any event, tracklist reappeared, but only bottom five tracks (out of total of 29) as well as Cancel and Add Disc buttons. Impossible to scroll remainder of tracklist into view.
14. Unable to proceed further with adding new release and forced to abandon effort.

Please advise if further information and/or further testing would be useful. Am also not convinced that I followed workflow correctly, but am stymied over where I might have gone wrong. The "howto" on entering a new release follows the workflow of the "classic" interface.