Unable to Launch Published Applications from XenApp 6

Symptoms

You are unable to open published applications from XenApp 6 and receive the following error messages:

“Cannot connect to the Citrix XenApp server.
The Citrix XenApp servers are reporting full load and cannot accept your connection at this time.
Try to connect again after a few minutes. If you continue to receive this message, contact your Citrlx administrator.”

“Unable to Launch your application, Contact your help desk with the
following information: Cannot connect to the Citrix XenApp server.”

“Protocol Driver error”

Cause

Several configuration options might prompt these errors.

Consider one of the following solutions below to resolve the errors:

Resolution 1

Check that the Web Interface XML configuration is set properly.
Open Citrix Web Interface Management.
Select XenApp Web Sites.
Click on Server Farms on the far right of the window pane.
Click on Edit:

a. Ensure that the correct XML broker(s) are listed under server.

b. Verify that the correct XML port is entered inside XML Service Port.

Resolution 2

Ensure that both RDP and ICA listeners are not set to a specific network adapter.
From the XenApp Server(s) open Administrative Tools.
Remote Desktop Services
Remote Desktop Session Host Configuration
Select RDP listener:

Right click go into properties and verify all network adapters are selected:

After verifying all Network Adapters are selected, review the ICA adapters (only applies to XenApp 6 / Windows 2008 R2 x64). Click on Start > All Programs > Citrix > Administrative Tools > ICA Listener Configuration.

Resolution 3

Ensure XenApp 6 policies are configured correctly.
Open the Citrix Delivery Services Console.
From the left pane, select Policies .
Select Computer from right pane and edit the unfiltered policy.
When the Identify your policy window opens, click Next.
Review your policies and enable the following settings:

a. License Server Host

b. License Server Port

c. XenApp Product Edition

d. XML Service Port

Save the Policy.
Run gpupdate /force from server command prompt.

Resolution 4

Ensure that you have registered the correct the port on the XenApp 6 server(s):
From the XML broker(s) (XenApp Server) open Services.msc. Ensure the Citrix XML service is started.
If the service is not started, you might need to register the correct XML port on the server and restart the service:

Resolution 5

Always clear Local Host Cache on all servers in farm to ensure a fresh copy of the datastore subset is applied to the XenApp and Zone Data Collectors.

Though IIS and XML can share the same port by default during an initial installation of XenApp 6, it is recommended as a best practice to assign a different port (for example: 8080) to XML

The "Cannot connect to the Citrix MetaFrame Server. Protocol driver error." Error Message is Displayed when Connecting to a MetaFrame Server

Symptoms

The following error messages that are displayed when connecting to a Citrix MetaFrame server:
If you enable Session Reliability, then the following error message is displayed:
Cannot connect to the Citrix MetaFrame Server. Protocol Driver error.

If you disable Session Reliability, then the following error message is displayed:
Cannot connect to the Citrix MetaFrame Server. The Citrix MetaFrame server you have selected is not accepting connections.

Note: The ICA-TCP and RDP-TCP listeners are enabled on the Citrix MetaFrame server. Additionally, the options to log on to the server are enabled.

You might also observe the following issues:
You are not able to connect to the port 1494, the Independent Computing Architecture (ICA) port, of the server by using the telnet utility.
You are not able to connect to the port 3389, the Remote Desktop Protocol (RDP) port, of the server by using the telnet utility.
When you run the NETSTAT -a command, the output of the command does not display that the server listening on port 1494.
When you run the NETSTAT -a command, the output of the command does not display that the server listening on port 3389.

Resolution

To resolve the issue, complete the following procedure:
Open the Systems Properties dialog box.
Activate the Remote tab.
Select the Allow users to connect remotely to your computer option, as shown in the following screen shot:

Note: You cannot make remote connections to the server, if you do not enable the Allow users to connect remotely to your computer option.

Error: Cannot connect to the Citrix server.

SYMPTOMS

A domain user, logged on to a Windows 2000 Professional Workstation, can browse for the list of applications and servers by a custom ICA connection. When the domain user tries to connect, the following error message appears:

Cannot connect the Citrix server.

If the domain user is added to the Power Users or the Administrators group, connection succeeds.

CAUSE

Applying the basic workstation policy provided by Windows 2000 Profesional, Basicwk.inf, prevents domain users access to the MSLicensing key in the workstation registry.

Domain users have insufficient rights to the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSLicensing key in the workstation registry.

RESOLUTIONS

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. Back up the registry before you edit it.

1. Run Regedt32 and give full control to the above MSLicensing key for domain users.

2. From the policy, enable the permissions for domain users to the MSLicensing key in the registry.

Cannot connect to Citrix XenApp server

We have used below steps of above article and got solution:-

Resolution

1. Verify that the Session Reliabilit​y port is reachable.​ This port is set in the Management​ Console by default as port 2598 and is configurab​le. Use the command line utility, Telnet /?.

2. Ensure that the port used by Session Reliabilit​y is not being shared by any other service, such as ICA, XML, IIS, or SQL. Use the command line utility, Netstat /?.

3. Ensure there are no Citrix Licensing issues or Product Code mismatches​.

4. Ensure the configurat​ion file, httpd.conf​, exists under the Citrix\XTE​\conf folder

5. Copy C:\Program​ Files\Citri​x\XTE\logs\x​te.pid from a good server. Note: When the XTE service is stopped, the XTE.pid file disappears​. If permission​s on the directory have been restricted​, then it is possible that the XTE service will not start as it cannot create the pid file. This file essentiall​y only holds the process ID of the XTE service.

6. Ensure the Citrix XTE service is started.

7. If the Citrix XTE service is started, Citrix may advise that the ICA listener be deleted, the system rebooted, and the listener recreated.

8. As a test, add the account for the XTE service from Network Service to Local System OR change the account for the service to Local System. Check permission​s on the C:\Program​ Files\Citri​x\XTE directory make sure that the Network service account has full rights

9. Users were unable to launch published applicatio​ns if the Session Reliabilit​y feature was enabled and an option other than All network adapters with this protocol was configured​ for the ICA protocol in the Citrix Connection​ Configurati​on utility.

This fix introduces​ support for session reliabilit​y even if you limit a protocol to a particular​ network adapter.

To enable this functional​ity:

a. Open the file httpd.conf​, located in the Program Files\Citr​ix\Xte\conf folder, in a text editor.

b. Below the line #Citrix_En​d, add the following line:

CgpSpecifi​edIcaLocalAd​dress

c. Save your changes.

d. Restart the server.

If you have this functional​ity enabled, assign a static IP to the server or, if you are using DHCP, create a script to automatica​lly update the IP address of CgpSpecifi​edIcaLocalAd​dress in the httpd.conf​ file. If the IP address of CgpSpecifi​edIcaLocalAd​dress does not match the actual IP address of the server, you receive an error stating that there is no route to the specified subnet address.

The remote sesssion was disconnected because there are no terminal server license servers available to provide a license

1. Go to Start->RUN->(Type) Regedit

2. Right Click on My computer-> Export->Save it on local disk.

3. Go to HKEY_Local_Machine->Software->Microsoft->MSLicensing.

4. Right Click on the folder(MSLicensing) and delete.

5. Restart the computer