This morning when I launched IceDragon I noticed I lost all saved bookmarks and saved passwords. These Bookmarks and passwords were not sent from Firefox. Is there any way to retrieve this stuff, as I heavily rely on these bookmarks and saved passwords.
If you still have the Bookmarks and Passwords on Firefox, you can use a “Firefox Account” (Options->Firefox Account).
The Bookmarks and Passwords can also be imported from Firefox on installation, by ticking the “Import from Firefox” checkbox.