You might see this message when connecting to your published XenAPP desktop.
The remote session was disconnected because there are no Terminal Server License Servers available to provide a license.
In a production environment we will of cause have to take a closer look at the RDS License Server, but in a small lab environment running with temporary client licenses, this might be expected.
If we take a closer look at the XenApp server you can find the event id 1001:
The remote session could not be established from remote desktop client xxx because its temporary license has expired.
We now know that this is related to the use of temporary licenses and we can temporary fix it until next time the license expires.
On the client with the problem open regedit and locate the key HKEY_LOCAL_MACHINESOFTWAREMicrosoftMSLicensing.
Then delete or rename this key and next time you start your published desktop it will recreate the key and a new Temporary CAL will be assigned on the server.
Also be aware that since we are dealing with a HKLM key you must be able to use elevated rights when deleting the key and when recreating the key!