State of knowledge

November 2022


If the ProCall client is to be started in a Citrix environment, the following error message appears:

"ProCall cannot be started because the ProCall icon could not be created in the taskbar notification area."


To use ProCall as a published application under XenApp or Presentation Server without restrictions and error messages, (at least) the following requirements must be applied:

  • ProCall must be configured as 'seamless' via the Citrix Server configuration in order to create the tray icon on the local Windows desktop.

    The seamless flags are stored in the server configuration under the following registry key:


    Value Name:SeamlessFlags
    Value Type: REG_DWORD

Setting options

The value of this parameter is calculated from a collection of properties that are more or less well documented.
They can also be configured for specific applications via the Windows class names, but this is generally discouraged

A passable collection of setting options can be found here:

The DISABLE SYSTRAY AGENT parameter must NOT be set for ProCall.