The terminal server might not be able to locate the license server.
Perform the troubleshooting procedures described in The terminal server cannot locate the license server.
The client might have exceeded its Terminal Server Licensing grace period (http://go.microsoft.com/fwlink/?LinkID=48895), and a license server has not yet been installed or activated to issue the client a client access license (CAL). After a temporary license expires, a client can only connect to a terminal server if the license server can issue a permanent CAL.
Install Terminal Server Licensing, activate the license server, then purchase and install a sufficient number of CALs to support the clients in your organization. As a security best practice, consider Using Run as (http://go.microsoft.com/fwlink/?LinkID=48886) to perform this procedure.
To install Terminal Server Licensing
Open Add/Remove Programs in Control Panel.
Double-click Add/Remove Programs.
Click Add/Remove Windows Components.
In Terminal Server Licensing Setup, do one of the following:
* Click Your entire enterprise to choose an Enterprise license server. You can only install an Enterprise license server on a domain controller or a member server in a domain (if the member server is running Windows Server 2003), not on a stand-alone server. This role is published to Active Directory. If you are installing an Enterprise License Server, you must meet one of the following conditions: 1) You must be a member of the Enterprise Admins group in Active Directory or 2) You must have the right to create the TS-Enterprise-License-Server object in the same site in which the license server will reside in Active Directory.
* Click Your domain or workgroup to choose a Domain license server. If you select this option, the computer on which you install the license server does not have to be a domain controller, if the computer is running Windows Server 2003. However, if the computer is running Windows 2000, the computer on which you install the license server must be a domain controller or a stand-alone server in a workgroup. If the computer on which you plan to install the license server is in a workgroup, it can only be automatically discovered by terminal servers on the same subnet. If you are installing a Domain license server, you must be a member of the Administrators group on the local computer. If the computer is joined to a domain, members of the Domain Admins group might be able to perform this procedure.
Provide the file system location where the license server database should be installed on the Terminal Server license server, click Next, and then click Finish.
The default location for the license server database is systemroot\System32\LServer.
You can activate a Terminal Server license server by using one of three methods: Automatic, Web Browser, or Telephone. It is recommended that you activate a license server automatically, as described in the following procedure.
To activate a license server automatically.
Open Terminal Server Licensing. To open Terminal Server Licensing, click Start, point to Control Panel, Administrative Tools, and then click Terminal Server Licensing.
In the console tree, right-click the license server that you want to activate, click Activate Server, and then follow the instructions in the wizard.
In the Activation method list, select Automatic connection (recommended), and then click Next.
Follow the instructions in the wizard.
If necessary, at a later time you can change any license server properties, such as activation method and company information, that you set during the activation process.
Best Regards :)