Silverlight not working on 2012 R2 RDS host

Question

Versions:
2012 R2 Server as RDS host
IE 11.0.9600.16518
Silverlight 5.1.20913.0
Firefox 27.0.1
A department needs access to a Silverlight application hosted here https://client.capturerx.com/cumulus
I'm moving this department from 2003 Terminal Services to 2012R2 RDS.
I installed Silverlight by downloading the silverlight 64 installer and installing it via control panel>install programs on Remote Desktop Server while logged on as administrator
As a standard user (no policies yet applied) Silverlight does not show up in IE addons, even when I select Show: All Add ons
In Firefox, the plugin is available, and configured to allow storage, but will not let a silverlight plugin cache itself or any data. 
A silverlight test site seems to run OK in Firefox bubblemark .com / silverlight2 .html
I don't know what else to try. Any help is appreciated

Answer 1

Hi,
As a test I logged on to a 2012 R2 RDSH server as an administrator, opened IE, and browsed to the following link:
http://www.microsoft.com/getsilverlight/get-started/install/default.aspx
I installed Silverlight and then logged on as a regular user, opened IE, and browsed to the Silverlight application page you listed above and it came up fine.  Additionally, I see Silverlight listed in the IE Manage Add-ons.  I did not test with
Firefox.
Based on the above I would recommend you try uninstalling Silverlight via the control panel, restart, and then try the install again from the above link.
-TP