Citrix Web interface 5.0 through 5.3 is not compatible with .Net 4.0 on a Windows 2008 Server

Symptoms

Web Interface site displays the message "The requested string could not be found" and gets into an infinite loop. The Web Interface is hosted on a Windows 2008 server with .Net 4.0.

Cause

Web Interface is not compatible with .Net 4.0.

Resolution

It is currently recommended not to install .NET 4.0 on a Windows 2008 Web Interface server that is using Web interface 5.0 through 5.3. If you cannot uninstall .Net 4.0 then complete the following steps for each of the affected sites:

1. Open Internet Information Services (IIS) Manager.
2. Click on the Web Interface site with the issue.
3. Select Handler Mappings.

1. Open each of the Citrix Web Interface executable paths.
2. You can notice that they are pointing to .Net 4.0. Change the path to point to .Net 2.0. Note that on 64-bit servers there is an entry for 32-bit and for 64-bit. Ensure that the path corresponds to the correct framework folder, example:
• CitrixWebInterfaceMappings-ica-32 –> %Windir%Microsoft.NETFrameworkv2.0.50737aspnet_isapi.dll
• CitrixWebInterfaceMappings-ica-64 –> %Windir%Microsoft.NETFramework64v2.0.50737aspnet_isapi.dll

1. Click OK.
2. Click Yes in the Edit Script Map notification.

1. Run an IIS reset.

This document applies to:

• Web Interface 5.0
• Web Interface 5.1
• Web Interface 5.2
• Web Interface 5.3

Source: Error: The requested string could not be found