I added a new portal - this itself was difficult due to an error that said "portalID already exists" after it had created the portal. However, I deleted the spurious portals, and attempted to edit the single good instance, raising this error:
Anybody have a suggestion on how to deal with this condition?

IF your DNN is not a root install  [for instance it is in a directory, /DNN6], then you need ...

www.Domain.com and www.Domain.com/DNN6 as aliases

If it is a child portal you need www.Domain.com/DNN6/ChildName as an alias also.  [DNN6 may have changed this latter part]

In  a shared hosting world, I have had situations where I had to wait for the 'web' pointers to eventually settle and point to the portal as well. I had two last week that 'healed' overnight...

What the world needs is a good explanation of how DNN and portal aliases work [the algorithm] as I [non-programmer] just have to trial-and-error it.  DNN6 gave me fits with forwarded and masked domains that inexplicably broke...

Bob,
User

I have 4 portals not including Portal 0, the host portal, and DNN is installed in the root (c:\inetpub\www). After reading your post I checked the directory structure and discovered the portal I described had been added in the root folder, rather than in the portals folder.