Mozilla is trying to beef up extension security in Firefox 3 by ensuring that the updates are provided by a secure address. All of the extensions on the official Mozilla add-ons site will work perfectly with this new system, but there could be problems when venturing outside of the site.
An example of this happened when I tried to install a development release of Tab Mix Plus. I was prompted with a message that said:
“Tab Mix Plus” will not be installed because it does not provide secure updates
As expected there is a hidden setting that you can adjust to prevent Firefox from checking the address from which an extension retrieves its updates. Here’s what you have to do:
- Start Firefox.
- In the Address Bar type “about:config” and press Enter.
- Right-Click and select New->Boolean.
- A box requesting the Preference Name will popup and you should enter “extensions.checkUpdateSecurity” (without the quotes). Press OK to continue.
- Select “False” from the box and press OK again.
After that you should be able to install your extensions just as you normally would. Disabling this feature could pose a security risk though, so be careful with what extensions you install when this is disabled.