So you’re trying to look at some cool link you’ve come across that shows something funny in Google streetview, for example, horse-boy (now sadly removed), or trying to spy into your neighbours bedroom in a not-in-any-way-creepy sort of way and streetview doesn’t work with Firefox. Meh.
What’s the problem?
Apparently, a few things can go wrong, such as plugin clashes or, like me you may simply have forgotten to alter a setting in Flashblock, for example.
Some possible fixes:
Clear your cache, etc. in FF.
If you use Flashblock so you don’t suddenly develop photo-sensitive epilepsy or have had enough of cleaning up that pesky bloodstain caused by your eyes bleeding thanks to those tasteful flashing ads on most webpages, you need to whitelist Google. Yes, it’s that simple. Go to the settings for Flashblock and whitelist (in my case) maps.google.co.uk.
If you have it installed, MediaWrap plugin has been reported to cause problems so disabling it should get streetview working properly again.
And finally, sometimes Flashplayer itself can be the cause. This can usually be cured by downloading the latest version from Adobe to your desktop and installing it after you close Firefox.