Setting up a new user for team foundation server, although user has been added to all the licencing groups and project groups, they cannot expand the root node of the team collection. They can also not access the portal security pages as it gives the above error.
Turned out to be that they needed the access level for the user setting.
This is outlined within the document here: https://docs.microsoft.com/en-gb/vsts/security/change-access-levels
You may follow this route to the access level admin (in the version we use)
Select Security from the Team Explorer Settings menu from Visual Studio
Navigate to the root of the control panel
Navigate to the Access Levels tab
Put the user under the appropriate access level of Basic or Advanced. This should then allow them to access the web portal without error and expand the source control collection node to see the individual projects (assuming you’ve set them up correctly with those too).