When i open F12 in my IE11 and go to the Watches Tab to see (and change) the JS values, i only get "<not available>" as a value. See this screenshot (sorry but stackoverflow won't let me post images inline yet :sigh:)
I only an see real values when JS execution is stopped, which is quite bothersome.
I'm not sure what i did (maybe a setting) but i think that worked some time ago. And also the MS Doc says, it should work, see https://msdn.microsoft.com/en-us/library/gg699336%28v=vs.85%29.aspx#watchvariables