Avoiding grey user agents
Q I have just tried to switch Safari to using HTML5 video playback as you suggested in MF275, and have got to the final step, select ‘User Agent’, but all the options are greyed out. It’s stuck on Default (Automatically Chosen) and I can’t see where to switch off Default. Alan Hunt
A Almost certainly, this is simply because you don’t have a browser window open. The user agent is set on a window-by-window basis, so that developers can have the same page open in different windows, each one pretending to be a different browser. So if you have all the windows closed, the user agent menu is greyed out, because there’s nothing for it to apply to.
Another, much less likely cause is a browser toolbar or other extension that was installed by one of those downloads that is almost-but-not-quite malware. Go to user-agents.me/whats-my-user-agent and see what it says your user agent is currently set to. If you are running the latest version of OS X and Safari, it should be Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_4) AppleWebKit/537.77.4 (KHTML, like Gecko) Version/7.0.5 Safari/537.77.4
If you don’t see that – and in particular if you see something like BLNGBAR tacked on the end – a rogue extension is probably the cause. Click Safari > Preferences > Extensions and disable or uninstall anything you don’t recognise and see if you regain the ability to change your user agent.
You can’t set the user agent unless you have an open browser window for it to apply to.