For what it's worth, I've also had the mentioned problem with FF39.

My alternative browser is Opera. No problems with file names when downloading.

For those not familiar with Opera, it is built on top of the Chrome platform but has more privacy options than the Google version. It also uses more temp storage memory than FF which is why I prefer the later.

When you have expanded the image, right click on the page (not the actual image) and "save page as" . This saves the image with the correct filename and extension. Hope this makes sense.

someone buy coolperson a drink!

It is only this site that I get attachment.php as the filename when I try to save a pic. Something is wrong with this site.

I wish it was a simple fix. It's not just a problem on this site. It's a problem on all forums using the vBulletin software the way we do. However, it was triggered by a change in Firefox between versions 38 & 39 and it appears that they are now doing something non-standard across web browsers in the way they handle HTML headers.

Don't get me wrong. I'm not playing the blame game. I want to see this fixed as soon as possible and we are working on it on our end. I'll post here when we have a new solution.

Wow. This is a really simple solution to an annoying problem. Thanks coolperson.

Just a thought, perhaps coolperson's info should be put into a "sticky".
It might answer some questions before they get asked.

Firefox 40
 

Thanks for the advice on this thread, the 'attachment.php' issue had stumped me until I read this. Reverting to 38.0.5 worked just fine.

However I've just upgraded to Firefox 40 and can report, they've resolved the issue.

Thanks for the heads up on that! I immediately downloaded FF40, and the problem is indeed resolved.

Just accidentely upgraded firefox and the "image" issue was back :mad:

Tried using Crome, nope, SAME THING here... what the he** is this problem????

NO, this does NOT work at all!, Again this is only happening on this forum...