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I saw a pop-up that said the newest version of Firefox isn't compatible with my antivirus program, Avast. Why will Avast not work with Firefox 5.0? I downloaded 5.0 but have not installed it because of this.

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I downloaded 5.0 Firefox but haven't installed it. I saw a pop-up that said it isn't compatible with Avast. I do NOT want to stop using Avast. Why will Firefox 5.0 not work with Avast?

I downloaded 5.0 Firefox but haven't installed it. I saw a pop-up that said it isn't compatible with Avast. I do NOT want to stop using Avast. Why will Firefox 5.0 not work with Avast?

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If Firefox disabled some add-ons (especially extensions), it likely is because they include a list of compatible Firefox versions and haven't yet been updated for Firefox 5.

For more information on avast, see this thread: I have just updated Firefox on my desktop. In order to operate it had to disable avast, my open source excellent anti virus software - a surprise that Firefox is compatible! Is there an avast! update that is compatible? Or a fix from Firefox coming? | Firefox Support Forum | Firefox Help.