Suddenly started getting a crash notice every time I closed or 'hid' Firefox. This morning I gave up and opened Safari. Tried to then open Firefox to get a password and found the entire app was gone. I had to go to Mozilla and load it again. It loaded with all my info so it must have been on my Macbook Pro somewhere? I THINK this started after a recent OS update on my Mac, which has included lots of annoying changes, esp to Mail. FYI, I'm running Sequoia 15.6. Why is this happening and is there anything I can do to solve it?