I am using a cisco 2901 with IOS 15.4(3)M2 with any connect pkg 3.1.05160
I can login via http , but when I using the any connect client I always get the error message below.
The service provider in your current location is restricting access to the Internet. You need to log on with the service provider before you can establish a VPN session. You can try this by visiting any website with your browser.
PC is my Apple Mac Pro and Windows 7.0 , note I can login using my iPad and iPhone with out any issues
the error message that you are seeing is due to the false captive portal detection.
If "ip http server" is enabled on IOS (which is required if the same box is used as PKI Server), AnyConnect falsely detects captive portal. The workaround is to use "ip http access-class" to stop responding to AnyConnect HTTP requests, instead of requesting authentication
please see the below document for further details: http://www.cisco.com/c/en/us/support/docs/security/anyconnect-secure-mobility-client/118086-technote-anyconnect-00.html#anc8