Cannot attach subscription

Hello,

I am attempting to attach a subscription to an offline RHEL 6.9 VM residing on Vsphere so that I can provide it with updates. I have followed the instructions in the knowledge base "3.5 Registering an offline system."

I have created a machine in the systems tab and configured it properly, then I went to the subscriptions tab in order to associate my subscription (RHEL Server Entry Level, Self-support) to this machine. I then attempt to attach my subscription. My applicable subscription shows up, saying that it requires one entitlement out of the four that I have available. I select it and press attach subscriptions. When I do this, I get a vague error message. "There was an issue attaching one or more subscriptions. Please try again."

So I've tried creating systems and selecting other options like changing it to a physical machine with one socket, virtual machine with one processor, etc etc to see if any of it would work and it did not.

If anyone needs further clarification please ask. I tried to be as thorough as possible but I may have not clarified important things.