Since this is a paid service, you might check with their support to see whether it is a known problem with Firefox 14, and whether they have a workaround.

What application previously handled the export? If you know the application and the file format (e.g., CSV), you might be able to fix how Firefox is handling it by making a change here:

orange Firefox button or classic Tools menu > Options > Applications

Edit: I assume that the problem is when you ask for an export, you get a window or tab full of data. However, if you can't even request the export, that would be a different problem.

Sagepay don't know. They just say it's a browser problem Duh! What happens is you click export and get a pop up box that gives you a choice of CSV or text. Think it's javascript. but as you can see from image the pop up box is just script and can't click on anything.

Can't rind any reference to CSV in the applications. Is there a way of downloading earlier Firefox version?

Perhaps I should ad that it's fine in IE but downloads in different format that means I would have to redesign all my forms.

Could I suggest that rather than reverting to an insecure version of Firefox as your main browser, you access that particular site using the Portable edition of Firefox? You need to close regular Firefox in order to run it. I'm guessing that if you go back 3 versions it probably will work as intended: http://sourceforge.net/project/downloading.php?groupname=portableap.... Hopefully Sage will catch up in the near future so you won't be inconvenienced.

In case the problem is an add-on conflict, a standard diagnostic is to try Firefox's Safe Mode.

First, I recommend backing up your Firefox settings in case something goes wrong. See Back up and restore information in Firefox profiles. (You can copy your entire Firefox profile folder somewhere outside of the Mozilla folder.)

Next, restart Firefox in Firefox's Safe Mode (Diagnose Firefox issues using Troubleshoot Mode) using

Help > Restart with Add-ons Disabled

In the Safe Mode dialog, do not check any boxes, just click "Continue in Safe Mode."

If the site works correctly, this points to one of your add-ons or custom settings as the problem.

Any change?

Aaah well. I had already tried safe mode and that didn't work but (before I read the portable bit) I found a downloadable version of 13. I blew it the first time by forgetting to switch off updates so it turned into 14 again. So, to be on the safe side I restored the system back 24 hours reinstalled 13 and everything is fine now. Suspect a clash with Java as there was an java upgrade in the interim but I only use Firefox for Sagepay anyway so I'll live with 13 until the problem is sorted. Thanks though! I was tearing my hair out.

For future reference, Windows' system restore feature only has very limited influence on Firefox; as far as I know, it only affects Firefox's registry settings. If you want to back up or restore your other Firefox settings, Windows' system restore doesn't help there.

In that case my best guess would have to be a clash with the most recent Java update. I have it set to 'ask' before installing and system restore will have reversed the installation but I'll let it run tomorrow and see if it affects 13 and let you know.