Hello,

Could you goto about:config and search for browser.download.useDownloadDir

then double click the preference and set it to false if it is not already. Let me know if that helps you.

Thanks,

Sir.Mayo

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

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

Thanks sir.mayo and cor-el, that was fast :). @sir.mayo : already tried that, but as expected, it was already setup to false. @cor-el : pretty sure it's not going to help, since I already tried to delete all firefox config files, then started firefox, and I was still having the problem. But i'm gonna try it anyway.

Now now ! Starting in safe mode WAS actually helpful, but in the strangest way. ° Starting Firefox without any extension at all (well, without anything at all, deleting .mozilla folder), I have the problem. ° Starting Firefox in safe mode, I don't have the problem. ° Starting Firefox normally again, then remove downthemall extension, restart, I have the problem ° Starting Firefox, reinstall downthemall, restart, now I don't have the problem anymore ...(I've tried removing downthemall a last time and now I don't have the problem even now, so I'm guessing downthemall IS the problem). Maybe it lets something in cache or outside .mozilla folder that is causing this behavior). Well, can't understand a thing, but it works, so I'm ok with it for now. Thank you everyone !