Citrix Studio/Web Studio showing LAS NotActivated

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Article ID: CTX696518

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Updated On:

Description

The Citrix License Server is successfully registered and activated with License Access Service (LAS). However, when attempting to activate LAS from Citrix Studio or Web Studio, the status shows:

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On the Delivery Controller, the following event is logged:
Event Viewer → Windows Logs → Application
Event ID 1300
The Citrix Broker Service will now stop providing desktop and application sessions. 
There is a problem with the system clock of the license server '<license server name>'

This issue can occur in environments where:
- The License Server and Delivery Controllers (DDCs) are in different Active Directory domains
- Each domain uses its own independent time source
-- There is a time difference (skew) between the DDCs and the License Server (e.g., ~20 minutes)


Cause

This issue is caused by a time synchronization mismatch between the Delivery Controllers and the License Server.LAS activation relies on secure communication using time-sensitive authentication tokens. If there is a significant time difference (typically greater than 5 minutes):Token validation fails (due to invalid time window)Secure communication between DDC and License Server is rejected leading LAS activation fails and shows "Not Activated" on Citrix Studio/Web Studio



Resolution

Ensure that all systems (License Server and Delivery Controllers) are synchronized to a consistent and reliable time source.

1: Verify Time DifferenceOn both the License Server and DDC:
w32tm /query /status time /t
Ensure the time difference is minimal (ideally a few seconds, and less than 5 minutes).

2: Identify the Time SourceOn the affected DDC:
w32tm /query /source
This will show the domain controller acting as the time source.

3: Configure the Primary Time Source (PDC Emulator)In each domain, the PDC Emulator FSMO role holder acts as the authoritative time source.3.1:Identify the PDC Emulator:
netdom query fsmo
3.2:On the PDC Emulator, configure a reliable time source:
  • If external NTP is allowed:
w32tm /config /manualpeerlist:"pool.ntp.org" /syncfromflags:manual /reliable:yes /update
If external NTP is not allowed:Configure it to sync with the same internal time source used by the License Server
  • Alternatively, align both domains to a common internal NTP source
3.3: Restart time service and resync:
net stop w32time && net start w32time w32tm /resync /rediscover

4: Ensure DDCs Use Domain Time HierarchyOn each Delivery Controller:1. Verify configuration:
w32tm /query /configuration
Ensure:
Type: NT5DS
2. If not, reset to domain hierarchy:
w32tm /config /syncfromflags:domhier /update net stop w32time && net start w32time w32tm /resync /rediscover

5: Validate SynchronizationConfirm:
w32tm /query /status
  • Source should be a domain controller
  • Time difference with License Server should be minimal

6: Retry LAS ActivationAfter time synchronization is corrected:
6.1:Restart Citrix Broker Service (or reboot the DDC)
6.2:Re-attempt LAS activation from Citrix Studio / Web Studio

Issue/Introduction

Citrix Studio/Web Studio showing LAS Not Activated

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