Users cannot logon to TS 2012 R2 Foundation: "No licenses available"

1. Please Check the local group police on the terminal server.

Following policies should be configured:

Local Computer Policy -> Computer Configuration 
-> Administrative Templates -> Windows Components 
-> Remote Desktop Services -> Remote Desktop Session Host 
-> Licensing

- "Use the specified RD license servers" = Servername 

- "Set the Remote Desktop licensing mode" = Per User

2. Now we can delete also the Grace Period registry key 
    on the terminal server:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control
     \Terminal Server\RCM\GracePeriod

Note: you must take ownership and give admin users full control 
 to be able to delete this key.

Click the key you want to take ownership of.

On the Edit menu, click Permissions.

Click Advanced, and then click the Owner tab.

Under Change owner to, click the new owner, and then click OK.

3. Restarted the Terminal Server