After installing Cisco AnyConnect VPN Client on Windows 8 Enterprise x64 you may get the following error message after you log into your VPN and the client is establishing the connection: The Client Agent has encountered an error
To fix the issue open REGEDIT and browse to the following location:
If you are having the issue you will most likely have DisplayNamefirstname.lastname@example.org,%vpnva_Desc%;Cisco AnyConnect VPN Virtual Miniport Adapter for Windows x64
The DisplayName key should be set to Cisco AnyConnect VPN Virtual Miniport Adapter for Windows x64 this is the same name as the VPN Network Adapter which Cisco AnyConnect installs.
When you set DisplyName=Cisco AnyConnect VPN Virtual Miniport Adapter for Windows x64 restart the Cisco AnyConnect VPN Client and the connection should establish correctly.