Web Builder 15.3 stopped working

[ianjfree]

Since installing 15.3 I cannot get webbuilder to work at all. I get a flash on the screen and then nothing happens
I've tried uninstalling and reinstalling - even gone back to 15.2.3, but the same thing happens every time - just won't load
This is really serious because I can't update any of my web sites now

[WWBman]

Try rebooting your system.

[Pablo]

Maybe the application is blocked by your firewall or virussscanner?