Firefox Community Forum

I've loved Firefox for years but can no longer use it because I have been unable to resolve this issue. All was well, an update was done, and bingo, I got this message. I don't know how to fix it. I removed Firefox from my desktop and re-installed. Same problem.

"The bookmarks and history system will not be functional because one of Firefox's files is in use by another application. Some security software can cause this problem."

I just got a new Epson 3-in-one printer and tried to sign up for the warranty. I got a message that the warranty was expired... I went to the Epson support site on Firefox and Malwarebytes blocked the site as malware... It said I could add the site as approved, but I don't know how to do that. "https://www.epsoncom.com/my-account/home". The Epson site said I already had an account but my password was incorrect. I had an Epson printer more than ten years ago; I don't remember the password and they don't provide an option to reset it. HELP, PLEASE.

I have sound in Windows, but YouTube is dead quit. I have tried all that is suggested in Firefox help and some YouTube sites. Nothing worked. I have tried off the computer and restarted, but no change. My system is Windows 11, sound works, and the latest Firefox update installed. Question is this a YouTube tacit to stop NoScript and uBlock?