Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of.

You can try these free programs to scan for malware, which work with your existing antivirus software:

• Microsoft Safety Scanner
• MalwareBytes' Anti-Malware
• TDSSKiller - AntiRootkit Utility
• Hitman Pro
• ESET Online Scanner

Microsoft Security Essentials is a good permanent antivirus for Windows 7/Vista/XP if you don't already have one.

Further information can be found in the Troubleshoot Firefox issues caused by malware article.

Did this fix your problems? Please report back soon.

Please try deleting the pluginreg.dat file located inside of your Firefox profile.

You do not appear to have the correct Adobe Flashplayer installed for Firefox; it is not in the list of Plugins submitted with your question (Shockwave Flash followed by version #). It also may be disabled in Add-ons > Plugins.

• Adobe Flashplayer comes in several versions. One is for IE only (ActiveX) and one is for most other browsers (Plugin).
• In addition there are 32-bit and 64-bit versions. Firefox is a 32-bit browser and requires the 32-bit Plugin version.
• You can have both the 32-bit and 64-bit versions installed and the various browsers will use the correct version (-bit and ActiveX or Plugin).

To get the correct version use the affected browser (i.e., Firefox) and go to the following page to get the correct version; in this case, use Firefox to go to the link below, using Firefox you must SAVE the download to your hard drive, close all browsers, then run the installer you just downloaded. When updating Flashplayer, always update for both IE and Firefox.

• Link to download - get.adobe.com/flashplayer
• See - https://support.mozilla.org/en-US/kb/keep-flash-up-to-date-and-troubleshoot-problems
• See - https://support.mozilla.org/en-US/kb/install-flash-plugin-view-videos-animations-games

ComputerWhiz,

Thank you so much for your quick response. I tried downloading several of the malware scanners--and a fresh version of Firefox--and in my download folder I received 2 files for each program I downloaded. One file was empty and the other was an exe.part file. When I clicked the exe.part file I got an error message saying MS didn't know how to open it. Frustrating. I remembered I have AVG and ran that and found a few threats. So, good to be rid of those. I saw another response that said to check my plug-ins. When I did I noticed the Flash had a "never activate" status, which I switched to "always activate" and that seems to have done the trick.

Thank you again for your kind help.

TheOldFox,

Thank you for your quick response. I checked the add-on plug-ins, as you suggested, and saw that the Flash was on status "never activate." I changed it to "always activate" and that seems to have done the trick.

Thanks again for your kind help.

I had the same issue on Flash with the same error message at Pandora. Thank you for the solution.

Good. Glad it worked for you.