Unable to Connect to Silverlight Out Of Browser Application

PROBLEM

I am not able to record my Silverlight out of browser application. It fails to attach with the following errors:

Outer Exception Type: System.TimeoutException
Message: Wait for condition has timed out
HRESULT: 0x80131505 (Official ID (if app.) = COR_E_TIMEOUT, Error Bit = FAILED, Facility = FACILITY_URT, Code = 5381)
Call Stack:
at ArtOfTest.Common.WaitSync.CheckResult(WaitSync wait, String extraExceptionInfo, Object target)
at ArtOfTest.Common.WaitSync.For[T](Predicate1 predicate, T target, Boolean invertCondition, Int32 timeout, WaitResultType errorResultType) at ArtOfTest.Common.WaitSync.For\[T](Predicate1 predicate, T target, Boolean invertCondition, Int32 timeout)

at ArtOfTest.WebAii.Core.Manager.WaitForBrowserToConnect(Int32 browserIndexToWaitFor)

at ArtOfTest.WebAii.Core.Manager.LaunchNewBrowser(BrowserType browserToLaunch, Boolean waitForBrowserToConnect, ProcessWindowStyle windowStyle, String arguments)

at Telerik.TestStudio.Web.IERecorder.IERecorderManager.LaunchNewRecorder(Action`2 asyncCallback, FloatingUIMode mode, BrowserType browserType, String arguments)

Solution

This behavior appears on systems which have the MS15-049 security fix (KB3058985) installed. It is included in Silverlight version 5.1.40416 and later.

This security fix was addressed in Windows Updates on 12th of May, 2015. The patch prevents an elevation of privilege issue by restricting Silverlight applications running inside sllauncher.exe (the out-of-browser Silverlight container) to a low integrity level.

You may wish to uninstall KB3058985 security patch or downgrade Silverlight below version 5.1.40416 to allow recording the Silverlight OOB applications.