Cisco AnyConnect “Failed to initialize connection subsystem” Error When Connecting to VPN on Windows 7 or Windows 8

I just today I tried to connect to my work network from home using the Cisco AnyConnect client, for reference I’m using AnyConnect 3.1.05182 on Windows 8.1, and was unable to. I was immediately presented with an error before even being asked for a username and password, which said something was wrong with the client, as it hadn’t really had time to start any proper negotiations with the ASA.

A little bit of Googling revealed that the problem might have come from a recent Microsoft update, dated just a few days ago. I had noticed my machine downloading a few updates of late, and I’m nowhere near as diligent with testing updates on my personal machine as I should be, or as I am on any work related systems.

It turns out that this is indeed a bug with the latest set of Microsoft patches, and Cisco confirmed this here.

While Cisco have said ultimately the fix has to come from Microsoft, there is a workaround until a permanent fix is produced;

  • Close the AnyConnect client from the system tray
  • Navigate to the AnyConnect client install location, for example “C:\Program Files (x86)\Cisco\Cisco AnyConnect Secure Mobility Client\”
  • Right click on the vpnui.exe and click troubleshoot compatability
  • Pick “Try recommended settings”
  • Click “Test Program” and this will reopen the AnyConnect client
  • Repeat the same process again, but for vpnagent.exe
  • On the final test when the AnyConnect client opens again, you then find that you’re able to connect normally again. If you have Cisco support it would probably be valuable opening a TAC case and mentioning case number #115021112390273. This bug does also affect Windows 7 when IE11 is installed, and the same fix should work there too.

    .NET Framework Cleanup – Full Uninstall

    I came across a server today that had some horrible problem with the .NET frameworks on it, and none of the updates or service packs from Windows update would install. I couldn’t remove any of the .NET applications using either the App/Remove Programs GUI, or via the correct msiexec install strings. I’m not sure how the server came to be like this, but it was a problem I had to sort out and basically I was a little stumped, until I came across Aaron Stebner’s MSDN blog. He had a post about completely removing the .NET applications in their entirety.

    The application works on all versions of .NET and you can find it on his blog here
    Once you’ve run the cleanup tool, reboot and then you can just install the applications from Windows Update again. The application worked very well and once it was finished, all was well in the .NET world.