First try to do the same tasks in Safe Mode: Try Firefox Safe Mode to see if the problem goes away. Firefox Safe Mode is a troubleshooting mode that temporarily turns off hardware acceleration, resets some settings, and disables add-ons (extensions and themes).

If Firefox is open, you can restart in Firefox Safe Mode from the Help menu:

• Click the menu button , click Help and select Restart with Add-ons Disabled.

If Firefox is not running, you can start Firefox in Safe Mode as follows:

• On Windows: Hold the Shift key when you open the Firefox desktop or Start menu shortcut.
• On Mac: Hold the option key while starting Firefox.
• On Linux: Quit Firefox, go to your Terminal and run firefox -safe-mode
  (you may need to specify the Firefox installation path e.g. /usr/lib/firefox)

When the Firefox Safe Mode window appears, select "Start in Safe Mode".

If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, theme, or hardware acceleration. Please follow the steps in the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause.

To exit Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.

When you figure out what's causing your issues, please let us know. It might help others with the same problem.

There were many reports of this in early 2014. What happened was, Yahoo migrated a lot of user accounts to a different server, but those users were accessing the old server either with a bookmark or a home page setting. I think Yahoo Mail was supposed to redirect to the new server automatically but if this didn't happen, then the mailbox was broken in various ways and one of them was accessing attachments.

To work around this, try accessing your mail using one of these (whichever one seems most applicable):

• Yahoo home page: https://www.yahoo.com/
• My Yahoo page: https://my.yahoo.com/
• Generic mail redirect: https://mail.yahoo.com/
• AT&T Yahoo page: http://att.yahoo.com/

Make sure to bookmark the new address if it works.

Old thread: firefox wont dowload any attachments from yahoo mail, all other downloads work

Please read my full question. I have already stated in my original question that i have tried restarting with addons disabled, i.e. in safe mode. This did not help.

Thanks, but this does not help as I have not been utilizing a bookmark, I have been manually navigating to my email via mail.yahoo.com And as my question stated, I only have this problem in Firefox. Accessing my email via mail.yahoo.com on all other browsers does not result in this problem.

Did any of the other workarounds in the old thread help?

Nope. I had already found that thread and tried out its suggestions before making this post.

If you haven't already, could you conduct this test:

Create a new Firefox profile

This is in addition to and does not replace your existing settings.

A new profile will have your system-installed plugins (e.g., Flash) and extensions (e.g., security suite toolbars), but no themes, other extensions, or other customizations. It also should come with completely fresh settings databases and a fresh cache folder.

Exit Firefox and start up in the Profile Manager using Start > search box (or Run) -- type or paste the following and press Enter:

firefox.exe -P

Don't delete anything here.

Any time you want to switch profiles, exit Firefox and return to this dialog.

Click the Create Profile button, assign a name like April16, and ignore the option to change the folder location. Then start Firefox in the new profile you created.

Does downloading Yahoo mail attachments work any better?

When returning to the Profile Manager, you might be tempted to use the Delete Profile button. But... it's a bit too easy to accidentally delete your "real" profile, so I recommend resisting the temptation. If you do want to clean up later, I suggest making a backup of all your profiles first in case something were to go wrong.

I have the same problem. Only in Yahoo mail (Gmail works fine), only in Mozilla (Explorer works fine). I tried ALL proposed solutions from this webside, nothing works. Any other ideas? Thanks!

I wasn't precise: I can download attachements but a single one. If I want download 5 attachments at once, instead of zip file I get very small file without any particular type (file type: file)

Others have found that using an antivirus may make it difficult to download files, however since yours is for multiple attachments please also contact Yahoo Support.

Other solutions I have seen:

• Switch the themes of the Mail to "Basic"
• Turn off mixed content:

Starting in Firefox 23, if a secure page includes certain types of insecure content, Firefox blocks the insecure content and a shield icon will appear in the address bar. See this article for more information about the new mixed content blocker: Mixed content blocking in Firefox

To temporarily allow the mixed content to be displayed:

• Click the shield icon in the address bar and choose Disable Protection on This Page from the dropdown menu.
  

To allow insecure content to be displayed in all secure pages, enter about:config in the address bar and double-click on this preference, to toggle it from true to false:

security.mixed_content.block_active_content

You can also use this add-on instead, to toggle the preference:

• Toggle Mixed active content add-on

You may want to do this only for the current session, then reset the preference back to "true" and check back with the site to see whether it's been fixed, since this is a global setting that exposes you on all sites, not just the one you care about.

Let us know if this helps!

Thanks for answer. Unfortunately it didn't help. Switch the themes of the Mail to "Basic" - doesn't work "Turn off mixed content: "- I don't have sheld icon but padlock, so I can't do that.