Hello bkrueger,
I'm a little late to this thread, so I apologize in advance if some of this is redundant or if I am failing to address your query.
I took a look at the journal.0129.txt that you posted. From that journal it looks as if you attempted to create a C4R workshared model via the Initiate Collaboration workflow using your A360 Admin project; this operation appears to have succeeded. From this we can conclude that your A360 hub, your Revit installation, and your C4R entitlement are all correct.
However, it seems as though there may be some confusion about how A360 projects relate to Revit's (/C4R's) view of A360. In brief, an A360 project is visible from within Revit if all of the following criteria are satisfied:
[1] the user who is signed into Revit has a valid C4R entitlement
[2] the user is also a member of that A360 project
[3] the user is using a version of Revit that corresponds to the project's bound version.
So, for example, if the original user in journal.0129.txt launches Revit 2016 and attempts to browse A360, they will not see the Admin project. This is because the initiate collaboration workflow from Revit 2015 bound the project to that version of Revit. (note: any update or service pack of Revit 2015 will be able to access the project.)
Another example: let's say there is another user who has a valid C4R entitlement but has not been invited and accepted as a member of the project. When they browse A360 from Revit, they will not see the Admin project because they are not a member of that project. However, if you were to invite them, they would be able to see it.
To conclude, here is a "proof of concept" that one might use for exploring C4R:
[1] Two users (userA and userB) are granted a C4R entitlement
[2] userA creates a new project "testProject" on the A360 hub
[3] userA launches Revit and uses the initiate collaboration workflow to create a central model(s) in that project for use with Revit worksharing. (As a byproduct of this, the project gets bound to the major version of Revit used by userA)
[4] userA invites userB to testProject; userB accepts the invitation
[5] userB launches the same major version of Revit (though possibly using a different update/service pack) and browses A360
[6] userB can see testProject, and if they browse that project they can see the models posted by userA in step [3]
[7] userA and userB can both open and work in any of the models in testProject using standard Revit worksharing workflows. The central model is hosted in the cloud, associated with the A360 project testProject.
Hope this helps; if you have any further questions please don't hesitate to reach out to us.
Mike Lee
Autoesk C4R QA
Michael B. Lee
Principal QA Analyst