Windows 8.1

Resolving Mini WAN Miniport Code 31 Errors on Windows 8.1

Posted on by Matt Woodward

After a recent Windows update I could no longer connect to one of my VPNs using the native Windows VPN connectivity (i.e. not a client like Cisco AnyConnect). When I tried to connect from the networking charm (I think that’s what they call the bar on the right-hand side of the screen) it would hang for a while but never connect, and after that happened when I clicked on the networking icon on the lower right the charm bar wouldn’t even come back.

I figured it might be a driver issue so I opened up Device Manager and sure enough, under the network adapters section there were yellow exclamation marks next to every one of the WAN Miniports that show up after you try to connect to a VPN.

I found varying reports of how to fix the problem but here’s what worked for me.

  1. Try to connect to a VPN that will cause things to error out (the WAN Miniports didn’t even show up in the network adapter list for me until I did this)
  2. Open Device Manager
  3. Expand “Network adapters”
  4. Right-click every one of the WAN Miniport devices (I even did the ones that didn’t have a yellow exclamation point next to them) and do the following:
    1. Click “Update Driver Software”
    2. Click “Browse my computer for driver software”
    3. Click “Let me pick from a list of device drivers on my computer”
    4. Uncheck the “Show compatible hardware” box
    5. Under Manufacturer choose Microsoft
    6. Under Network Adapter choose “Microsoft KM-Test Loopback Adapter” (technically from what I understand you can pick anything that you can uninstall, but this one worked consistently for me)
    7. Click “Next”
    8. Ignore the “blah blah might be incompatbile” warning and click OK
    9. After Device Manager refreshes, right click the Microsoft KM-Test Loopback Adapter and click “Uninstall”
  5. After you’ve done that for every one of the WAN Miniports listed, reboot the machine. If you don’t do this things won’t be fixed.
That cleaned things up for me. We’ll see if it works on subsequent reboots.

Cisco AnyConnect on Surface Pro 3

Posted on by Matt Woodward

If you get the dreaded “failed to initialize connection subsystem” error when trying to use AnyConnect on the Surface Pro 3, or on Windows 8.1 in general for that matter (though it works fine for me on my ThinkPad T540p), there’s a lot of differing opinions on how to fix it so I thought I’d share the one that worked for me.

What absolutely did not work for me (but that apparently works for other people based on frequency with which I encountered this solution) is just running AnyConnect through the Troubleshoot Compatibility wizard. That had zero effect for me.
What did work is this:
  1. Hit the Windows key and start typing “AnyConnect” to bring up AnyConnect in the search/launcher thingee (as I call it)
  2. Right-click on AnyConnect and choose “Open file location”
  3. Right-click on AnyConnect in Windows Explorer and choose “Properties”
  4. Click on the Compatibility tab
  5. Check the “Run this program in compatibility mode for” box and select “Windows 7” in the drop-down
  6. If you have a high-resolution display and AnyConnect looks fuzzy, and you care, you can also check the “Disable display scaling on high DPI settings” box
  7. Hit OK to save the changes.
  8. Reboot for good measure.
There have also been some previous issues with IE 11 updates breaking AnyConnect (yeah, wrap your head around that one) but those seem to have been resolved as long as you have your machine all patched up.