False captive portal detect?

[Steve]

After several successful connected to ocserv, AnyConnect 3.1 on Mac
always complaints:

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.

Any fix or workaround for this issue?


Thanks,
Steve