NOTE – 08-02-2017, 8:53 AM: We believe the problem with Citrix and Horizon has been resolved. It is possible that users will have to logout of Citrix and back in before trying Horizon again. If you are still experiencing problems after logging back into Citrix, please contact the Help Desk for further assistance.
We are investigating a problem which is preventing logins to Horizon for many users and limiting access for others. We will send more information out as it becomes available. Thank you for your patience.