Several users reported this in a short period of time a few days ago. I don't think anyone tracked down what causes it.

Do you get that on particular websites (MSN was mentioned by one user)?

Since "impression" is a word associated with advertising, it may be that some ad-related script is malfunctioning. But that's just a thought.

Thank you. This hasn't solved my problem but it's interesting others have experienced the same. I am trying to find if it's a legitimate request to enable my system to function better or a scam. I will take more notice of when it appears.

To be clear: don't bother saving the file, just cancel the dialog.

Thanks but there is no point just closing it as it reoccurs repeatedly. I have refreshed Firefox but it's still there!

I suspect one of the sites you're visiting, or an ad embedded in the site, is not compatible with Firefox. However, I don't know why we don't have a lot more reports in that case. Maybe there is some contributing factor, such as a particular brand of security software? Or most people are using an ad blocker? If you want to try an ad blocker, this one is well regarded: https://addons.mozilla.org/firefox/addon/ublock-origin/

Hello, Microsoft says it's nothing to do with their system. Bitdefender says nothing malicious on my computer. Yes, it does appear to be MSN. I have saved and opened the file (both options offered) but it hasn't made any difference. I also did a refresh Firefox. I'm very frustrated. Biggest problem is that if I follow some options I don't know what I will lose as I already had to change Home page back and add in favourites to toolbar. I'm not a Luddite but don't have a college degree in computers either :-) Cheers....

PS: Is there an option anywhere to "talk" to a Firefox assistant?