I have a WebVPN SSL VPN built on a 3825. I also did this on a 7206 and had the same issue. It has a 15.1 IOS. I am using the most current AnyConnect client.
Most users can connect no problem. Some users get an error "The VPN driver has encountered an error" and cannot connect. I have had a case open for a month and haven't gotten any help from TAC. Most users have Vista, some have XP. Most have IE8, some have IE7. But there is no consistent pattern that I can see for those that get this error. I am including the vpn config below, but since most pc's can connect, I think the config is OK. I think I have to do womthing on the pC's maybe? But I have no idea. Anyone have any ideas
webvpn gateway vpn
ip address 10.1.18.5 port 443
http-redirect port 80
ssl trustpoint TP-self-signed-1529824412
inservice
!
webvpn install svc flash:/webvpn/anyconnect-win-2.5.1025-k9.pkg sequence 1
!
webvpn install svc flash:/webvpn/anyconnect-macosx-i386-2.5.1025-k9.pkg sequence 2
!
webvpn context vpn
logo file logo.jpg
secondary-color #006400
title-color #006400
ssl authenticate verify all
!
!
policy group policy_1
functions svc-required
timeout idle 86400
timeout session 259200
svc address-pool "vpn"
svc keep-client-installed
svc split include 10.0.0.0 255.0.0.0
svc split include 192.168.6.0 255.255.255.0
svc split include 192.168.7.0 255.255.255.0
svc split include 192.168.17.0 255.255.255.0
svc split include 192.168.16.0 255.255.255.0
svc split include 192.168.10.0 255.255.255.0
svc split include 192.168.8.0 255.255.255.0
svc split include 192.168.9.0 255.255.255.0
svc dns-server primary 10.1.2.20
svc dns-server secondary 10.1.3.32
default-group-policy policy_1
aaa authentication list sdm_vpn_xauth_ml_1
gateway vpn
max-users 250
inservice