Maybe you need to install or enable (Tools > Add-ons > Plugins) some plugins to be able to handle more types of media files.

• https://support.mozilla.org/en-US/kb/fix-common-audio-and-video-issues
• https://www.mozilla.org/en-US/plugincheck/

• https://support.mozilla.org/kb/Using+the+QuickTime+plugin+with+Firefox

• https://support.mozilla.org/kb/play-windows-media-files-in-firefox

   Flip4Mac: 

• http://dynamic.telestream.net/downloads/download-flip4macwmv.htm

Thanks for your reply, but I had tried all those links before posting. The quicktime link is installed, active, and the most recent version. It is set to open MP3 files. I have uninstalled it and re-installed it. It did not help. I find it strange that the MP3 files will play in FF after I play them in IE. However, that does not seem to be leading to a solution. I can't pinpoint when the problem started. Historically, this same site has not been a problem, so it must be an issue either with the current quicktime plugin or the current version of FF, or how they play together. I can play these files in IE, so it's not the end of the world.I would simply prefer to use FF.

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

• Do NOT click the Reset button on the Safe mode start window or otherwise make changes.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

You can delete the mimeTypes.rdf file in the Firefox Profile Folder to reset all file actions.

• http://kb.mozillazine.org/mimeTypes.rdf
• http://kb.mozillazine.org/File_types_and_download_actions#Resetting_download_actions

You can use this button to go to the Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder

've been using it forever and it just started crashing repeatedly every 5 minutes. I submitted reports with descriptions and my email but Mozilla never contacted me to help. I don't much care for Chrome or other browsers. So I tried everything. I went under Firefox's troubleshoot page and "reset" firefox. Didn't work. I uninstalled (including manually deleting any file on my computer regarding Mozilla) and reinstalled it. Didn't work. I even did a full restore on my PC. Didn't work. I have Mcafee and scanned and everything. No malware. I'm probably going to download version 3.6 if I can find a good download of it but can anyone help?