Documents that link to "Unable to install add-ons or extensions"
- Unable to install add-ons (en-US)
- Install language packs to get more languages for the interface of Firefox (en-US)
- Find and install add-ons to add features to Firefox (en-US)
- Websites say that Firefox is outdated or incompatible even though it's the latest version (en-US)
- Use themes to change the look of Firefox (en-US)