Why does Firefox keep doing this?

[Charlie]

I'll leave my computer for a couple minutes with my firefox browser open and I come back and it's been closed. Usually when it crashes it has a little pop up that says "Firefox has crashed bla bla bla" and what not. But not here, not the last three times this had happened. I reopen it and I have to restore my previous session all over again. It's frustrating me.
@leona,

Thank you very much! I was certain I wasn't even going to get an answer since most of these sections are so dead. I appreciate it. Do you remember what specific programs you had to delete by any chance? Thanks again!

[Leona]

This happened to me before. After a while when the websites you have opened haven't been touched for a few minutes, it closes. Yes, when I open it back I have the option of restoring my sessions, too. Usually when I'm on it but doing other tasks I often move my mouse around and click stuff so it won't close. I just deleted a few programs and it didn't happen again. Don't worry, it's not firefox or your device.

[Zino]

May be some plugin is causing this problem its better you reset you Mozilla Firefox . Reset will not remove your data so dont worry and then update your Browser

[Boss]

Reinstall it.