First make sure that there is not lock file or parent.lock file in your profile folder.

I have also seen this when the passwords file that stores passwords in your profile is locked or not readible. Right click on the profile folder to make sure its not hidden or read only for any of the files within that folder.

Second, update to the latest Firefox version.

This sounds very odd. It would help to see what you're talking about. Can you post screenshots of the respective preferences and describe the difference you're seeing?

If you need help to create a screenshot, please see How do I create a screenshot of my problem?

Once you've done this, attach the saved screenshot file to your forum post by clicking the Browse... button below the Post your reply box. This will help us to visualize the problem.

frank924 said

Each time click "Firefox - Preferences" I get only a partial display of options that normally shows up on my MacBook Pro (Mavericks). If I click on a different subtopic, close Preferences and reopen Preferences, I get a fuller display on THAT topic, but never have I been able to see "Saved Passwords" or "Change Master Password" on MacBook Air.

Turns out my Firefox app was not up to date, even though Preferences are set to update automatically (potentially another problem, but.... Problem solved with update. My other laptops (Mavericks).

Sorry to bother you.