Many times, browser crashes or even security vulnerabilities happen not because of the browser itself but the plugins that it uses.
Here is a quick way to check whether all your plugins in Mozilla Firefox are properly working or need to be updated in order to avoid any potential browser related issues :
1. Go to Mozilla Plugin Check.
2. Let the scan end, this will show a list of plugins that are installed for Firefox along with the status of each plugin.
3. Click the button in the Action column to update the plugin if necessary or to obtain further information related to it.