I have used Firefox for years, now all of a sudden, it will not always open when I double click on it. It does once in awhile, but then will crash while I am using it. Any clue why this is happening and what to do about it? A couple days ago I clicked on a Facebook page and when it went to the link, I got a blue page with a warning sound and words, cannot recall exactly what it said, but I backed out of it quickly and this trouble did not start right away, but am wondering if that has anything to do with it. I have Sofos antivirus and it assured me all was well when I ran a scan a few moments ago. I run on Windows 10 if that makes a difference.