Can you go into Manage --> Appliances as the Admin user? Click on the gear to the left of your LEM, pick "Connectors"
Click the "Configured" check box.
Are your Directory Service and Email Active Response connectors running? Sometimes they stop after an upgrade.
Once they're started, try logging out and logging in as your AD user.
PS: I found the thing I wrote when this became an issue in 6.0.1 and the steps are still good. I updated the document for you.