Extensions are broken in Firefox on my machine. I have Windows 7 and v16.0.2 of Firefox.
I'm having the following symptoms:
I'm able to install extensions normally. However, they do not take effect (don't show up in menus, context menus, or run). This is true for all extensions.
In the Add-ons Manager, when I click "Options" for an installed and enabled extension, the entire browser freezes and only killing the process exits the program
When I restart the browser I get a tab for each installed extension with the text "Another program on your computer would like to modify Firefox with the following add-on:"
There is never an extensions.sqlite file in my Profile (!)
When I check "Allow this installation" and press "Continue" the extension appears enabled
Even upon a clean reinstallation of Firefox (even deleting all folders), the issue persists
I've tried everything under the sun and I'm completely baffled. Anyone have ideas?
Alright thank you gentlemen, the combination of your advice fixed the issue. Certain files were not given permission to my profile folder. For reference, here's the logs:
The addons list was always being rebuilt since there was an NS_ERROR_FILE_ACCESS_DENIED error when calling XPIDB_writeAddonsList and XPIDB_openDatabaseFile. Then I guess it failed.
The solution was to create a new profile in a subfolder of my Users folder, where apparently there are no permission issues.
I imagine this is the result of some lovely corporate security policy gone haywire.
(edit: also posted as Answer below)