License Acquisition Error 500 Occurs and Workspace Control Fails
Article ID: CTX123372
Updated On:
Description
Users are unable to connect to XenApp farm and receive the following error message:
“license acquisition error (500): Unable to acquire a license from (server name) server. Please contact your system administrator or open the event viewer for more details."
If users connect through Web Interface and the Workspace Control feature is enabled, Web Interface might display the following error message on the Web Interface page:
“Your server farm is not licensed to support workspace control. This was reported by the xml services address xmlBrokerAddress.”
The following events might be logged in the server’s System Event Log:
EventID: 9014 Description: The licenses required by this edition of Citrix Presentation Server are not present on the license server LicenseServerName. EventID: 9017 Description: This computer running Citrix Presentation Server will now stop accepting connections. This server is no longer in or could not enter a licensing grace. EventID: 9026 Description: Error errorNumber received while obtaining a license for a Citrix Presentation Server client connection. A grace license has been granted. EventID: 9027 Description: Error errorNumber received while obtaining a license for a MetaFrame client connection. The license request has been rejected."
Resolution
This issue occurs when network communication between XenApp server and License Server is affected for any reasons. Citrix recommends to examine the health of the network connectivity between the affected XenApp server(s) and the License Server. In some cases, examining the log files and diagnostic tools of the network equipment revealed high amount of errors such as CRC errors. Replacing network cables, faulty switches or moving the servers to different switch ports can resolve the issue.
Updates have been released to increase resiliency of XenApp to network problems and delays.
Citrix Licensing - Latest download
If the latest updates are applied and the communication problem occurs, the XenApp Server will re-initialize the connections to the License Server. This returns the persistent connection between the XenApp Server and the License Server to a stable state, if no further network problems occur. It is important to note that during the re-initialization of the connection, all licenses checked out by the affected XenApp server are checked in and immediately back out once the re-initialization completes.
The following System Event Log messages might appear:
On XenApp for Windows 2008:
Source: MetaFrame EventID: 9034 Description: A Citrix licensing request has timed out. This might be an indication of communication problems between this server and the license server. As a result, the server has reinitialized its connection with the license server. All licenses checked out by this server have been checked back in and attempts will be made to check the licenses out again
On Presentation Server 4.5:
Source: MetaFrame EventID: 9030 Description: A Citrix licensing request has timed out. This might be an indication of communication problems between this server and the license server. As a result, the server has reinitialized its connection with the license server. All licenses checked out by this server have been checked back in and attempts will be made to check the licenses out again.
On Presentation Server 4.0:
Source: MetaFrame EventID: 9031 Description: A Citrix licensing request has timed out. This might be an indication of communication problems between this server and the license server. As a result, the server has reinitialized its connection with the license server. All licenses checked out by this server have been checked back in and attempts will be made to check the licenses out again.
Note: If the events are logged repeatedly users can still connect to XenApp. However, the errors indicate network problems that must be investigated.
As a step to eliminate the issue, it is recommended to modify the license server property in the Management Console for the affected server(s) to some arbitrary server and then back to the valid Citrix License Server. If the affected server(s) inherit their license server information from farm settings, deselect Use farm settings and change the license server property per server.
Problem Cause
This behavior is observed when there are intermittent network problems, or delays (over 10 seconds per message) affecting the communication of messages between the XenApp server and the License Server. After a timeout of a message sent from the XenApp server to the License Server occurs, subsequent communication to the License Server does not occur correctly because the persistent connection from XenApp to the License Server becomes unstable. As a result of the instability of this connection, subsequent user connections to the XenApp server might fail with the previously noted errors.
Important! This issue only occurs in cases where the License Server is online and partially accessible over the network from the affected XenApp server. If the License Server is completely offline, this problem does not occur because the XenApp server continues to accept user connections until the standard licensing grace period expires or the License Server becomes accessible, whichever comes first.
A common source of this problem is intermittent network connectivity issues because of a physical problem such as damaged or defective network hardware (patch cables, patch panels, or switch ports).
Issue/Introduction
Additional Information
