VPN Connection authentication popup

I keep getting this popup over everything if I'm connected to wifi, with no vpn connected. Goes off when not connected.

I've been onto my vpn provider but they can't help. I ran a prefs script that they suggested (see below), fully deleted other vpn software, and I've run everything in TechTool Pro 9.

When I run network diagnostics I get a weird result, as I am connected to the internet (browsing fine):

Also, and I don't know if these are related, but at the same time tht this problem started I can't connect to App Store, and ITunes won't quit or see my AppleTV 2. Mail is also misbehaving. All other non-Apple software running fine. Fully ant-virus protected. After six days of troubleshooting I'm at wits end.

I connect to web sites fine with Firefox. My ISP has confirmed no problems their side.

The script:

Last login: Thu May 3 10:16:24 on console

/Users/xxx/Downloads/removePrefsScript ; exit;

My-Mac:~ xxx$ /Users/xxx/Downloads/removePrefsScript ; exit;

logout

Saving session...

...copying shared history...

...saving history...truncating history files...

...completed.

Deleting expired sessions...none found.

[Process completed]