After upgrading to 6.3.1.x I login with my iOS device using webAgent and it says "Your webPass extension is out-of-date"
This means that you need to go to webAdmin Dashboard, click on Customization Center, then Upgrade Center. Find the profile(s) that you use for all of your users and make sure it is up to date. Once you do this it should not ask to update webPass for webAgent devices.