This article covers troubleshooting issues encountered when users attempt and fail to connect to XenDesktop virtual desktops. These issues are identified using the event log messages produced in the Desktop Delivery Controller (DDC) device.

Background

When the user requests a connection to a virtual desktop, a number of tests are performed and checks made to select the correct virtual desktop to which they must be connected. If one or more of these tests fails in some way, the desktop launch is refused and the user is informed that the resource is unavailable. An event log message is also produced on the DDC machine describing why the launch was refused, and this article is to aid troubleshooting these situations.

No Desktop Machine is Available (Event 1101)

No suitable desktop machine was found which was ready to satisfy the failing launch. This might be because of some machines being marked as in maintenance mode, or simply running out of desktop machines. Either add more desktop machines to the site using the Desktop Studio console, or remove the maintenance mode setting on one or more of the relevant desktops or machines using the Desktop Studio console or the Broker PowerShell SDK.

Desktop Machine Refused Connection (Event 1102)

The agent software running on the select desktop machine actively refused a request to make the machine ready to accept a connection from the user. If registry-based controller discovery is in use, which is the default mechanism, ensure that the desktop machine in question has been configured with a list of controllers that includes the controller that attempted the failed launch. See CTX118976 - How to Configure XenDesktop to Function Without an Organizational Unit in Active Directory.

Examine the event log on the desktop machine in question for further error indications, and if necessary use logging of the workstation agent service to capture traces of the launch sequence actions.

Desktop Machine Session Already Active (Event 1103)

The desktop whose launch failed was already running a connected session for the user and active session reconnected has been configured to be disabled. If active session reconnection must be allowed, change the value of the DisableActiveSessionReconnect registry entry. See CTX126704 - Registry Entries Used by XenDesktop 5.x Broker Service for a description of this and other registry entries.

Desktop Machine in Maintenance Mode (Event 1105)

The desktop or machine selected to be used for the launch is currently flagged as being in maintenance mode. This might be because the user already has a session on that machine, which prevents the system choosing to use another machine for that user, or the machine might be permanently assigned to the user. Either remove the maintenance mode setting on the desktop or machine using the Desktop Studio console or the Broker PowerShell SDK, or end the running session on the desktop or remove the permanent assignment.

Requested Protocol Type is Not Supported (Event 1106)

The protocol requested to be used for the failing launch, for example HDX or RDP, is not supported to be used with the selected desktop machine. The protocols, which are supported, can be configured through the Broker PowerShell SDK, using the cmdlets relating to the Access Policy Rule (see the ‘about_Broker_AccessPolicy’ help topic).

Application is Disabled (Event 1107)

VM-Hosted application, which defines the failing launch application, is marked as disabled. If required, enable the application through the Broker PowerShell SDK, using the Set-BrokerApplication cmdlet.

Desktop Machine already has a Session (Event 1108)

The desktop or machine selected to be used for the launch is already running a session, and this session is not suitable to be used in the failing launch circumstances. This might occur if a desktop has been permanently assigned to a user, but then a different user logs on to the machine, for example through the machine console. End the running session on the desktop or remove the permanent assignment.

Desktop No Longer Available (Event 1109)

The desktop group, which would provide the desktop for the failing launch is marked as disabled or has been deleted. If the desktops available to the user are re-evaluated, for example, the user logging on to Web Interface again, this resource would not be offered to the user. If required, enable the desktop group through the Broker PowerShell SDK, using the Set-BrokerDesktopGroup cmdlet.

Other Launch Failure (Event 1100) or Other Launch Failure on Reconnect (Event 1104)

If the launch failure cannot be categorized to a particular failure reason, one of these events occurs.

Machine Start Failures (Event 3012)

The behavior occurs when XenDesktop fails to start the required machine for the requested session. If the machine is running on a hypervisor, this might occur when the hypervisor is Off, the hypervisor does not have enough resources to launch the virtual machine (for example out of memory) or VDA is in maintenance mode.

The connection to "virtual_desktop" failed with status (1110)

Unable to access XenApp/XenDesktop with internet error: "The connection to "virtual_desktop" failed with status (1110)".
To resolve this, change self-signed Root CA certificate common name from wildcard to regular one. The applications/desktop can be launched.
Refer to Citrix Discussions: Failed with status (1110) and CTX200890 - Error: "Failed with status 1110" When Launching Desktops or Apps Through NetScaler Gateway.

Troubleshooting Actions

If the preceding descriptions of the event circumstances do not provide sufficient clues to determine the problem, logging of the Citrix Broker Service must be used to capture traces of the launch sequence actions. So, collect CDF tracing, and select the following modules to be traced:

• CdsController

• CdsBroker

• CdsXmlServices

• ControllerDAL

• BrokerDAL

• CdsLicensing

• CdsHostingManagement

• CdsTicketStore

• CdsHostingPlugin

• CdsInterService

• PRODLIC_Library_Common

• PRODLIC_LicPolEng

This article covers troubleshooting issues that are encountered when users attempt and fail to connect to XenDesktop virtual desktops.