Hello,

In order to better assist you with your issue please provide us with a screenshot of the kind of error message that is appearing. If you need help to create a screenshot, please see How do I create a screenshot of my problem?

Once you've done this, attach the saved screenshot file to your forum post by clicking the Browse... button below the Post your reply box. This will help us to visualize the problem.

Thank you!

The 32-bit Firefox 48.0 runs on Windows XP. However the Win64 Firefox needs 64-bit Windows 7, 8 (8.1), 10 to run.

Maybe you changed the shortcut for Firefox to run in compatibility mode set to Windows XP ?

philipp said

Hello, In order to better assist you with your issue please provide us with a screenshot of the kind of error message that is appearing. If you need help to create a screenshot, please see How do I create a screenshot of my problem? Once you've done this, attach the saved screenshot file to your forum post by clicking the Browse... button below the Post your reply box. This will help us to visualize the problem. Thank you!

philpp,

Please see attached image. Thank you for your assistance with this issue.

Dan

James said

The 32-bit Firefox 48.0 runs on Windows XP. However the Win64 Firefox needs 64-bit Windows 7, 8 (8.1), 10 to run. Maybe you changed the shortcut for Firefox to run in compatibility mode set to Windows XP ?

James,

That's my next attempt. I'll let you know if this worked or not. Thank you for your assistance with this issue.

Dan

thanks dan, that looks like a fraudulent message that might be caused by malware on your system, so please perform all those steps:

1. refresh firefox (this will keep your bookmarks and passwords)
2. afterwards go to the firefox menu ≡ > addons > extensions and in case there are still extensions listed there, disable them.
3. finally run a full scan of your system with different security tools like the free version of malwarebytes and adwcleaner to make sure that adware isn't present in other places of your system as well.

Troubleshoot Firefox issues caused by malware

philipp said

thanks dan, that looks like a fraudulent message that might be caused by malware on your system, so please perform all those steps:

1. refresh firefox (this will keep your bookmarks and passwords)
2. afterwards go to the firefox menu ≡ > addons > extensions and in case there are still extensions listed there, disable them.
3. finally run a full scan of your system with different security tools like the free version of malwarebytes and adwcleaner to make sure that adware isn't present in other places of your system as well.

Troubleshoot Firefox issues caused by malware

philipp,

I think I got the issue solved. I right clicked on the desktop shortcut, chose restore previous versions. In the Compatibility tab the "Run this program in compatibility mode for:" box was checked. I unchecked it, apply and ok. Started FF and it has been working without issues since. The user will let me know tomorrow first thing if this fix worked.

Thank you again for your assistance.

Dan

DH67 said

James said

The 32-bit Firefox 48.0 runs on Windows XP. However the Win64 Firefox needs 64-bit Windows 7, 8 (8.1), 10 to run. Maybe you changed the shortcut for Firefox to run in compatibility mode set to Windows XP ?

James,

That's my next attempt. I'll let you know if this worked or not. Thank you for your assistance with this issue.

Dan

James,

The "Run this program in compatibility mode for:" box was checked from the desktop shortcut. I unchecked the box and FF is running without issue.

Thank you again for your assistance.

Dan

Oops it was a legitimate notice generated by your network then - it looked quite phishy to me in the beginning...

philipp said

Oops it was a legitimate notice generated by your network then - it looked quite phishy to me in the beginning...

Yes, it's a legit notice.