Today I tried to install some new browser extensions into the latest Firefox 0.9.3 browser and couldn't figure out why nothing was happening. I first tried opening the XPI file directly from the Mozilla Update extensions page. I clicked on one of the extensions I wanted (Adblock, highly recommended), and clicked the "Install Now" link. Nothing happened, like it wasn't recognizing my click.
Next attempt: Download the XPI file, and try to install it that way.
I saved the adblock-0.5-dev.xpi file to my disk,
then went into Firefox's File / Open File... menu to open it.
Nothing happened. It was like Firefox was just going to ignore the
fact that I asked it to open the file.
Next attempt: Drag the XPI file from the folder into Firefox and have it open
the file that way.
Still, nothing happened.
I went to the Tools / Extensions menu item to see if something was
stopping me from installing extensions, an error message, something.
I searched around the Internet looking for people with similar problems.
I checked out the Firefox help on Firefox forum.
Nothing pointed me in the right direction.
I tried hunting around in all my Tools / Options... settings to see if
something there would help me out.
Tools / Options / Advanced / Software Updates / Allow web sites to install software.
There it was.
I had, many months ago, unchecked this box for security reasons when
I first installed my browser.
Even though I was installing the XPI file locally and not from a web site,
that security option was stopping the extension from being installed
(which is a good thing).
Summary: User error.
Firefox was doing exactly what I had told it to do.
While I'm suitably chagrined,
it sure would have been nice if Firefox would have told me
what I was doing wrong rather than ignore my attempts to install the XPI files.
How about an error dialog, "Your security settings prohibit installation of browser extensions."
Next stop: A check of the bugzilla site to see if this feature is on the to-do list.
Bugzilla has this problem logged as
were filed by others similarly frustrated.
It looks like someone wrote a patch for it,
so maybe the fix is in the nightly builds even now.
But I'll wait until Firefox 1.0 comes out to enjoy the fix.