It's strange that prefs.js and about:config do not match.

You can edit prefs.js in a text editor to remove that entire line. However, please fully quit out of Firefox first so that the file is not in use or overwritten.

The problem is that the file is read-only for some reason. I cannot edit it.

Did you check the properties of the file and check the permissions and the owner?

You can try to repair the disk permissions:

• http://thexlab.com/faqs/repairprocess.html

I've seen evidence in other threads that these files are expected to be read-only, no?

The user_pref("extensions.installCache", line is also set to a whole mess of C: drive files. That can't be right, either.

I don't know how THAT happened, unless at some point I was trying to import bookmarks or something from a Windows copy of firefox. It's a mystery.

No, all files in the Firefox profile folder need to have read/write permission. Otherwise Firefox won't be able to update or delete the file and you are left with that read-only copy. It is only not recommended to edit the file, but in special cases you may have to do that and if you know what you do then that shouldn't be a problem. You only need to make sure that Firefox is closed when you want to make changes to files in the Firefox profile folder.

So check the permissions of the file(s) in the profile folder and make sure that you have write permission.

How can I change the write permission on Mac OS 10.6.8?

I think I've been being a big dummy. I'm very very sorry. This prefs. js file is the one on my Windows partition, for when I am running Firefox in Windows XP. ughhhh. And that version of firefox is running fine. But that's why I can only read that file. I don't even SEE the prefs.js file on the mac side.

OK, so then.

"Always ask me where to save files" is not working on the mac side. And I have NO idea why.

To confirm which profile folder is active when you are running Firefox, it is easiest to open it from inside Firefox as follows:

Sometimes the file that stores the customizations becomes corrupted and fails to update properly at the end of your session. You can rename the file and customize from scratch.

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information

In the first table on the page, click the "Show in Finder" button (Windows: "Show Folder" button).

Hopefully you are using a separate profile folder on each OS.

OK, that's great. I was able to find the prefs.js file, and it DOES match the about: config page. But my download problem remains a mystery.

When I am using gmail in firefox, I can download attachments to the download/firefox folder, but I _cannot_ use "Always ask me where to save files." No dialog box comes up allowing me to choose where to save files.

And I don't know why.

In hopes this will help lead to a diagnosis and fix, I'm having the same problem (FF doesn't ask where to save the download after I selected in options that FF should ask where to save) on Windows 8.1 with FF 31.0.

Hi spicetrader, did this problem just start after you updated Firefox to version 31, or can you associate it with any other changes on your system (new add-on, etc.)?

Have you tested in Firefox's Safe Mode? That's a standard diagnostic tool to deactivate extensions, some advanced features, and some custom settings. More info: Diagnose Firefox issues using Troubleshoot Mode.

You can restart Firefox in Safe Mode using either

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• (menu bar) Help menu > Restart with Add-ons Disabled

Note: Flash and other plugins still run

After Firefox closes, a small dialog should appear: click "Start in Safe Mode" (not Reset)

Any difference?

@jscher2000...

Thanks for your attention to this situation. I did run Firefox as you suggested, clicking on the ? icon and choosing to restart with Add-ons Disabled. First I checked the setting was "Ask me where" and then tried a download. The problem persists. FF doesn't ask me.

FF put the download in C:\Users\[userid]\AppData\Local\Temp

I'm not sure whether the problem started with version 31 or not. It performs the same way on a newly-set-up machine and on my old machines. I just got weary of the problem and went searching for a solution.

Delete a possible user.js file and numbered prefs-##.js files and rename (or delete) the prefs.js file to reset all prefs to the default value including prefs set via user.js and prefs that are no longer supported in the current Firefox release.

• http://kb.mozillazine.org/Preferences_not_saved

You can use this button to go to the currently used Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)