XenApp License acquisition error -18

Last Updated on May 18, 2020

Citrix XenApp license acquisition error (-18): Unable to acquire a license from (SERVER NAME) server. Please contact your system administrator.

Event ID – 12306 | Source – CPS Licensing

You may get that error when launching published Application or Desktop from Citrix XenApp 6.5. Why am I writing about it now? Because I encountered it recently and the setting that resolved this issue is not a very common fix for XenApp License acquisition error -18.

The plan was to segregate licenses for Citrix Virtual Apps and Desktop 1912 LTSR site and Citrix XenApp 6.5 farm by reallocating 600 concurrent (300 each) licenses to two license servers. First license server (11.16.3.0 build 29000) on Windows Server 2019 Datacenter Edition will be used by CVAD 1912. Second license server (11.14.1.1 build 21103) on Windows Server 2008 R2 will be used by XenApp 6.5.

Post changing the License server name in Citrix Policy through AppCenter, I used following PowerShell command to execute gpupdate on all target devices. Since only License Server host name, which is a computer policy setting,was modified, using Computer in Target parameter refreshes only computer policy settings.

Invoke-GPUpdate –Computer “FQDN\Computer Name” –Target Computer

The change took effect immediately. On target devices, you can verify the License Server name at HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Citrix\IMA\Licensing\LicenseServerHostName.

Then when users started launching applications and desktop, they got “Citrix XenApp license acquisition error (-18): Unable to acquire a license from (SERVER NAME) server. Please contact your system administrator”.

This error was historically associated with User IDs that are defined in upper case in AD (NIGUP instead of nigup) or a user name that contains a string “UD”. Citrix even released a hotfix XA650R01W2K8R2X64002.MSP for this error in September 2012. We had it installed as a part of a rollup pack and none of the user had his/her username in upper case. I found one another Knowledge Center article (CTX221460) from Citrix that was not very resourceful.

One another system event (Event ID – 9014, Source – MetaFrame) was frequently showing up along with 12306 – The license required by this edition of Citrix XenApp are not present on the license server License server fqdn.

I checked XenApp Product Edition setting was set to Enterprise, which is equivalent to Advanced edition. Since we have Citrix Virtual Apps and Desktops Advanced Concurrent licenses, the setting seemed to be correct.

Quick search on Google for “The licenses required by this edition of Citrix XenApp are not present on the license server” landed me at CTX133234. The article suggests changing the XenApp Product Model setting to any of the below values according to the Licenses purchased:

• XenApp – when you have XenApp standalone licenses.
• XenDesktop concurrent system – when you have XenDesktop Concurrent System licenses and you would like to license the XenApp component.
• XenDesktop user/device – when you have XenDesktop user/device license and would like to license the XenApp component.

I checked XenApp Product Model setting was set to XenApp that seemed correct.

Fixing XenApp License acquisition error -18

Finally, I escalated it to Citrix Support. I knew that due to COVID-19 situation, Citrix has a very limited support on weekends but to my surprise, an executive called back. Let us give it up to Citrix Support this time. Just after 10 minutes of conversation, she asked me to change the value of XenApp Product Model setting to XenDesktop Concurrent from XenApp and reboot target devices.

At last, error “Citrix XenApp license acquisition error (-18): Unable to acquire a license from (SERVER NAME) server. Please contact your system administrator.” was gone when users launched applications after the reboot. “The license required by this edition……….” also disappeared from Event Logs.

Learning (At least for myself)

XenApp/XenDesktop

XenDesktop and XenApp Licensing: FAQ

If you receive XenApp as a component of the Enterprise or Platinum Edition of XenDesktop, your XenApp license model is the same as your Enterprise or Platinum Edition of XenDesktop. You can select XenApp as a product model only if you have XenApp Concurrent standalone licenses installed on the license server.

Virtual Apps/Virtual Apps and Desktops

Virtual Apps and Desktops Licensing FAQ

If you use Citrix Virtual Apps as a feature of Citrix Virtual Apps and Desktops Advanced or Premium Edition, your Citrix Virtual Apps license model is the same as your Advanced or Premium Edition of Citrix Virtual Apps and Desktops. If you have purchased Citrix Virtual Apps and Desktops, configure your licensing as Citrix Virtual Apps and Desktops even if you plan to use only the Citrix Virtual Apps functionality. Select Citrix Virtual Apps as a product model only if you have Citrix Virtual Apps concurrent standalone licenses installed on the License Server.

Changing the Product Edition and Model in Virtual Apps and Desktops

Open Studio, expand Configuration, Select Licensing and then under Actions on the right, click on Edit Product Edition

Identifying License Type

Although Manage Licenses or All Licensing Tools (Legacy) areas in your Citrix account should clearly tell what type of license you own, below table can be used to identify the license type by matching the Product Code in first column with the INCREMENT line in the license file. The license file is saved at C:\Program Files (x86)\Citrix\Licensing\MyFiles.

An INCREMENT line describes the license required to use a product.

Syntax: INCREMENT feature vendor SA_expiry_date exp_date num_lic \

Example: INCREMENT XDT_ENT_CCS CITRIX 2020.1231 permanent 300

Good Reads

1. Citrix Virtual Desktops Licensing – Increment Lines Explained
2. Identifying Different License Types
3. Understanding License File
4. License Compatibility Matrix