Citrix Clipboard Redirection causes Session Disconnect

This week I had to troubleshoot a Problem where a lot of Copy and Pasting in a published Desktop caused the XenApp Session to freeze or disconnect.

The Customer reported a Problem where some of his Users were getting disconnected as soon as they ran a specific Excel Macro. At first I suspected that the Macro used some kind of Screen Refresh or something similar which would cause the ICA/HDX Session to disconnect or frezze but the Macro only involved copy and pasting a lot of information in quick succession. That led me to focus on the Clipboard Redirection because everytime I copied a large amount of Data my Session frozze up.

Solution: We finally fixed the Session Disconnects by disabling the Clipboard Redirection via Citrix Policies because the Customer solely relies on published Desktops and therefore he doesnt need to copy and paste things between the XenApp Systems and the Endpoints.

If you need the Clipboard Redirection to be enabled and want to avoid the Session Disconnects/Freezes you should try the new Citrix Receiver 3.1 Cumulative Update 1 or downgrade to the Online Plug-in 12.x.

Note: This Problem should also apply to XenDesktop as long as you use the Receiver 3.0 or 3.1 which seems to be affected with this "Clipboard Redirection Bug".

Update: This should be fixed in the Receiver 3.2 aka Online Plug-in 13.1.200.x or later.

EdgeSight and the Payload Error

During a Performance Troubleshooting I noticed that some EdgeSight Agents weren't uploading their Performance Data to the EdgeSight Server.

Under the "Configure" > "Company Configuration" > "Agents" > "Run Worker" Tab some of the EdgeSight Agents indeed showed the following Error:

Error: -2147209300 SendPayload error: Invalid data returned from server

In the Windows Event Viewer under the Applications Tab were also many Warnings with the Event Source: ASP.NET 2.0.50727.0 and the Event ID: 1309. 

After some research it all came down to the MS11-100 Security Patch ( from Microsoft regarding an ASP.NET Vulnerability.

There is also a Citrix Support Article regarding this Problem: and a fairly large Thread in the Citrix Support Forums here:

Solution: My "quick and dirty" Solution was to remove the Security Patch from the EdgeSight Server and after rebooting the Server all the EdgeSight Agents were able to upload their Performance Data successfully. I guess the better Solution is to play around with the "MaxHttpCollectionKeys" Value in IIS (as described in the MS and Citrix Article) and to not remove the Security Patch.