Unless OP is being specifically blocked by Humax, the TV Portal should still be accessible, despite only being useful as way of getting to BBC iPlayer TV. No BBC Radio, thanks to the BBC moving that to another app, or series of them, that were never ported to the HD/Rs; no 'rewind live TV' as that's not been implemented for the HD/R app; the YouTube app no longer works thanks to pointless forced https-isation of the site that isn't supported by the OpenSSL 1.0 API assumed by portal apps.
The HDR that I'm looking at now has the new-portal package installed and I can certainly launch that Portal and from there the original Humax Portal, which also offers BBC Sport and News apps (if you accept the Humax Privacy Policy) for the next 2 months until they are withdrawn. Other apps are tumbleweed with the exception of "Internet Radio": I just had a blast of Elmore James from a Mexican blues station, but BBC stations are available in case anyone wants local radio that isn't on Freeview -- until some idiot decides that a trackable app is required.
One reason for the Portal failing is that the HD/R can't access the Internet, but that would also cause (eg) package updates to fail. OP could try posting the result of the Webif diagnostic cpdiag.
Discussion of Webif, its diagnostics, new-portal and youtube-dl really belongs in the CF forum, but doesn't conflict with OP's setup.