Atom link 'not a feed'?

[tedthetrumpet]

I use https://theoldreader.com/ to subscribe to the http://new-supercollider-mailing-lists-forums-use-these.2681727.n2.nabble.com/ via nabble. This has worked for years, but I just
noticed I've not had any new posts in that feed since May 24. Now, when I go
here to try to resubscribe to the feed:

http://new-supercollider-mailing-lists-forums-use-these.2681727.n2.nabble.com/template/NamlServlet.jtp?macro=feeds&node=2676391

… and use the link under 'topics and replies', the old reader says the feed
'cannot be validated', sending me here:

http://validator.w3.org/feed/check.cgi?url=http://new-supercollider-mailing-lists-forums-use-these.2681727.n2.nabble.com/SuperCollider-Users-New-Use-this-f2676391.xml

… which says this is 'not a feed'.

Any ideas?

[GregChapman]

You may be aware of this topic:
http://support.nabble.com/Forum-has-Changed-tp7600696.html
which appears to discuss a related issue.

I'm not an expert on feeds, but as an unregistered and un-logged in user user when I click your resubscribe to feed link I get sent to:
http://new-supercollider-mailing-lists-forums-use-these.2681727.n2.nabble.com/template/NamlServlet.jtp?macro=login_page&message=You+must+login+to+view+New+SuperCollider+Mailing+Lists+Forums+%28Use+These%21%21%21%29.&nextUrl=http%3A%2F%2Fnew-supercollider-mailing-lists-forums-use-these.2681727.n2.nabble.com%2Ftemplate%2FNamlServlet.jtp%3Fmacro%3Dfeeds%26node%3D2676391

The evidence suggests to me that on 24 May the user permissions were changed to prevent unregistered users from having access to the forum. (Maybe something more than that happened at the same time?)

[Israel <Nabble>]

Hello Ted,
Is everything working fine?