Juniper Terminal Services Client Stopped Working Suddenly

Juniper Terminal Services Client is a software for VPN access provided by Juniper Networks.

I encountered issue when it suddenly stopped working properly two days ago.

I began to realize that it was due to some Windows updates which happened three days ago. After checking out the Windows updates history, I found that I had installed Internet Explorer 11 during that time and I knew I couldn't be more right.

It seems like upgrading to IE 11 had caused this issue - tested with other PC with IE 6 and it worked normally.

This web site suggests that Juniper Terminal Services Client is only supported by the following web browsers:
  • Microsoft® Internet Explorer 6.0 SP1 and above on Windows®
  • Mozilla Firefox 1.5 and above on Windows and Linux®

Hence, since currently I am using Firefox version 26.0 and I have no reason to downgrade, I figure that it would be a much worthy effort to download my Internet Explorer to previous version by uninstalling the updates I did three days ago and guess what ?  I managed to get Juniper Terminal Services Client come back working.

Here are some tips:
  1. Downgrade IE 11 to previous version - which Juniper Terminal Services Client had worked - which in my case was IE 10.
  2. Uninstall Juniper Terminal Services Client - you can do that from control panel/programs.
  3. Reset IE settings to default - Internet Options/Advanced/Reset.
  4. Do not apply recommended security settings.
  5. Run IE as administrator - for those using Windows Vista and above.
  6. Go through the normal process of setting up Juniper Terminal Services Client.
    Check out information from this web site; on Windows 7 professional 32-bit, it was installed on '%APPDATA%\Roaming\Juniper Networks' which in my case was 'C:\Users\Brandon\AppData\Roaming\Juniper Networks' 
  7. Make sure that security software doesn't block - I am using free 360 and I found that it was detecting dsTermServ.exe as a potential threat.
dsTermServ.exe was detected as a potential security threat

There are three components that will be installed as a result of setting up Juniper Terminal Services Client:
  1. Juniper Terminal Services ActiveX - you need to 'Allow' it from IE.
  2. Juniper Terminal Services Client - you need to install it according to the instruction.
  3. Microsoft.VC80.CRT - this will be installed automatically if the above two processes were done properly.

The output folder (%APPDATA%\Roaming\Juniper Networks) will end up like this:

%APPDATA%\Roaming\Juniper Networks

%APPDATA%\Roaming\Juniper Networks\Host Checker

%APPDATA%\Roaming\Juniper Networks\Juniper Terminal Services Client

%APPDATA%\Roaming\Juniper Networks\Logging

%APPDATA%\Roaming\Juniper Networks\Setup Client

I would like to bet that without downgrading to IE 10, by reinstalling Juniper Terminal Services Client properly, it could work on IE 11 - I am not sure about this one as I do not wish to go through the hassle again - this took me one working day to figure out via trial and error.

Nevertheless, if it doesn't, it means Juniper Terminal Services Client doesn't work on IE 11.

I have also found that it works on IE 6 but doesn't seem to work on IE 8.

The trend of security updates is causing compatibility issues for the software industry and it is getting worst - this is the reason why Oracle invented the concept of Red Stack - all components work together seamlessly under a unified platform provided by a single vendor.