DisplayLink 7.6 software messing up Cisco VPN - giving a 442 error Failure to Enable Virtual Adapter


#1

Just received a Windows Surface Pro2 with Windows 8.1 64 bit on it from work and bought the Plugable 3.0 USB Docking station. Post installing the DisplayLink 7.6 software (downloaded latest version) I get two monitors working, ethernet, keyboard and mouse…all seemed to be OK. I go to VPN into work using Cisco VPN software 5.0.07.0440 and get a 442 error - failure to enable virtual adapter. I removed the Displaylink software and VPN works correctly again. Is there a fix for this?


#2

We responded to Scott via email, and are posting the pertinent portion of the email here for the benefit of others who may be encountering the same issue:

Usually when there’s any sort of conflict with something Cisco related, we see a handful of tickets about the issue, but I’m not seeing any other reports of this behavior.

Doing a bit of research led me to this thread which had a bit of useful information. The error code referenced is different than the 442 error that you’re receiving, but there is a link to a DNE patch that they report resolves some compatibility issues with the VPN software and Windows 8.1:
http://social.technet.microsoft.com/F…

In the past when there have been conflicts between Cisco software and DisplayLink drivers, Cisco has released updates to resolve the issue, so if the issue persists after the above patch, it might be worth bringing the issue to their attention as well:
https://supportforums.cisco.com/discu…

Also, we’ve got a log-gathering tool that will be helpful if we end up needing to escalate the issue to the DisplayLink team. It can be downloaded here:
http://plugable.com/support/plugdebug


#3

An update for the benefit of anyone who might be researching this issue: This Cisco VPN client is considered “EOL” by Cisco, and is not officially supported in Windows 8.1. (Though some have been able to get the client to work with various Registry hacks.)

However, even with the Registry modifications in place, it seems like this particular VPN client does not work properly alongside the DisplayLink drivers under 8.1.

As this VPN client is no longer supported by Cisco, it seems unlikely that they will address this with an update.


#4

I did find a manual work around…when logging in with VPN I have the Device Manager open and enable the VPN adapter during the handshake…and it connects and works properly after that with Displaylink software installed and configured.


#5