RD Web Access cannot load RemoteApps or Personal Virtual Desktops from a Connection Broker

When configuring a Windows Server 2008 R2 Remote Desktop Web Access server to load RemoteApps from a Connection Broker, the following error message is displayed:

RD Web Access was not able to contact the RD Connection Broker server specified. Ensure that the RD Connection Broker server name was entered correctly, and that the server is running and available on the network.

The Connection Broker server was not allowing the RD Web Access server to load RemoteApps because of the user right "Access this computer from the network". This user right did not have the proper group membership to allow the connection.  A group policy was being applied to all servers in the domain that removed the default users and groups from the Access this computer from the network user right.

If using a group policy to configure user rights, set the policy to not configured and the default users and groups will be added to the user right "Access this computer from the network".  The RD Web Access server should then be able to successfully load the RemoteApps from the Connection Broker.