Also in Device Manager, the httpstunnel interface had a yellow explanation mark.
This problem can be caused by a few things, one of the most common causes is the DisabledComponents DWORD not being set to 0 which in effect disables IPv6 which is required by Direct Access. Check this under the following registry key:
Note: If this registry key does not exist, it is the same as having it being set to 0.
Another issue which can cause this error is when the computer looses its trust with the computer account object in Active Directory. When you bring the computer in and plug it into the internal network, you will see one of these two errors:
The trust relationship between this workstation and the primary domain failed.