Hi,
he took me some times to understand and reproduce the issue.
I had some trouble that sometime, using the On Demand portal, I could not access the Layout of my project ending with that:

But we check twice witch my admin, and there was no issue on the permissions, all was properly setup.
Then I realized that this appears only when I use Safari of Chrome using a private session to navigate to the page.
Is this a known issue/behaviour made on purpose, or a possible fix to add in an upcoming update?
I'm use to connect to private session, in order to not kill other session I have open with different Adobe ID. (like in forums)