Hello Kay.

If you're missing your menu bar, press ALT or F10 in your keyboard to make the Menu Bar temporarily visible. If you want it to be permanently visible, go into View > Toolbars > Menu Bar, or right-click the Navigation Toolbar (the Reload button, for example) and select Menu Bar.

If this doesn't help, right-click the navigation toolbar, select Customize... and click Restore Default Set. If it doesn't appear right away, try pressing ALT or F10. You can go into View > Toolbars > Menu Bar to make it permanently visible, or right-click the Navigation Toolbar and select Menu Bar.

If none of this helps, you may be having a problem with some Firefox add-on that is hindering your Firefox's normal behavior. Try disabling all add-ons (just to check), to see if Firefox goes back to normal.

Thanks so much for this answer, Morbus! I was having the same problem, and you've helped me figure it out.

That worked