A pub​lished application is running from a network share as a mapped drive. In this example, the path to the executable is W:\windows\system32\notepad.exe. Launching the published application from a XenApp 6 2008 R2 servers generate the following error(s):
“Citrix online plug-in could not contact the server. Please check your network connection.”

“The remote server failed to execute the application launch request. Please contact your administrator for further details.”

The online plug-in refreshes the application. The server event viewer shows an error as following:
“Application XYZ is published to the server X, but the command line w:\windows\system32\notepad.exe is not valid on X. Verify the correct servers and/or work groups are assigned to XYZ and ensure that the application is installed on X.”
Where XYZ is the application name and X is the server name.

For the application to launch, the drive must be mapped first for the user launching the session. No error occurs while launching the application in a published desktop, however a published application fails.

For XenApp 6.0

1. Publish a batch file that maps the network drive and then calls the application. The path through UNC can also be published, however certain applications require a drive letter and are also run from a network share. A simple batch file for this example could be similar to the following code:
   net use w: \\server-name\share-name 
   w:\windows\system32\notepad.exe

2. Name this batch file my-app.cmd and save it to a local drive such as C:\. In the published application location, map to the batch file rather than the network drive location.
   Citrix has released a hotfix that can be used to disable the Application Installation Check.
   HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Citrix\IMA
   Name: DisableAppInstallCheck
   Type: REG_DWORD
   Data: 1 (allow published applications to reside on mapped network drives); 0 (do not allow published applications to reside on mapped network drives)
   Note: This issue does not occur in other versions of XenApp and Presentation Server.
   [From XA600W2K8R2X64016][#242170]

For XenApp 6.5

In XenApp 6.5, configure the application check using PowerShell:

1. Check the current state of the application. This example uses a published application named Notepad.

PS > Get-XAApplication -BrowserName Notepad
…
LoadBalancingApplicationCheckEnabled : True
…

2. Set the application to not check prior to load balancing:

PS > Set-XAApplication -LoadBalancingApplicationCheckEnabled $false

3. For more details run get-help Get-XAApplication:

-LoadBalancingApplicationCheckEnabled <Boolean> Enable application installation check during load balancing.Required? false Position? named Default value N/A Accept pipeline input? true (ByPropertyName) Accept wildcard characters? false

Problem Cause

XenApp 6.0 adds a new check called the Application Installation Check during load balancing to ensure that the published application exists on the server. The Citrix Services Manager service now ensures that the file specified in the application command line exists on the server selected by load balancing. If this check fails, the error message listed above in the event log of the server is displayed.

The application installation check retries load balancing up to five times to return a valid server to the user. This check is intended to prevent a few misconfigured servers from creating a black hole condition in the XenApp farm. However, administrators must always make sure that applications are installed at the correct locations on the correct servers, and not rely on this check for day-to-day load balancing.

CTX131514 - How to Disable Application Installation Check Option in XenApp 6.5
CTX966450 - How to Publish an Application Using a Shortcut (.lnk file)