Troubleshooting Silverlight extension installation

How to check if the Silverlight Extension has been correctly installed?

Installation Steps

  1. Uninstall Microsoft Silverlight from Control Panel


  1. Confirm with a Demo Link ( that Silverlight Runtime is no longer installed.
  2. Install the latest Silverlight Developer Runtime (5.1.50918.0 as of 1/8/2020 ):
Note: Microsoft Silverlight reached end of support on Oct 12 2021 (see
  1. Close all Silverlight pages
  2. Go in Studio → Tools → Silverlight Extension


Manually install from Administrator CMD: C:\Program Files (x86)\UiPath Studio\v8\UiPath\slinject.exe /install This command displays more information in the console about installation.

Troubleshooting Steps

If there are still issues with extension installation, check also:

  1. Confirm existence of:

C:\Program Files (x86)\Microsoft Silverlight\5.1.50918.0\agcore.debug.dll
C:\Program Files (x86)\Microsoft Silverlight\5.1.50918.0\dbgshim.dll

  1. Uncheck “Read only” attribute of (right click -> Properties -> “General” tab)

C:\Program Files (x86)\Microsoft Silverlight\5.1.50918.0\
C:\Program Files (x86)\Microsoft Silverlight\5.1.50918.0\System.Windows.dll

  1. Confirm content of C:\Program Files (x86)\Microsoft Silverlight\5.1.50918.0\System.Windows.ini , the values GenerateTrackingInfo=1 and AllowOptimize=0 should be noticed by opening it with Notepad

  1. Confirm registry key HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Deskover\UiPath has SLInstalled value 1