If content is missing or otherwise not working then check if there is a shield icon to the left of the "Site Identity Button" (globe/padlock) on the location bar indicating that content is blocked.

• https://support.mozilla.org/kb/how-does-content-isnt-secure-affect-my-safety
• https://developer.mozilla.org/Security/MixedContent

• https://addons.mozilla.org/firefox/addon/toggle-mixed-active-content/

There is no such icon.

Clear the cache and cookies only from websites that cause problems.

"Clear the Cache":

• Firefox/Tools > Options > Advanced > Network > Cached Web Content: "Clear Now"

"Remove Cookies" from sites causing problems:

• Firefox/Tools > Options > Privacy > Cookies: "Show Cookies"

Also make sure that your security software isn't blocking the attachments.

Boot the computer in Windows Safe Mode with network support (press F8 on the boot screen) as a test to see if that helps.

I tried the above. I am still unable to open attachments with Firefox.

Create a new profile as a test to check if your current profile is causing the problems.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer some files from an existing profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over the problem.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

I solved the problem by doing an uninstall and reinstall of Firefox

Sign out of Yahoo, sign back in, then try to download the attachment. Worked for me after days of frustration.

RNORTH

I solved the problem by doing an uninstall and reinstall of Firefox 

Glad that worked for you.
Whilst posters in this thread have the same broad and vague symptom the cause may vary. Reinstalling Firefox may be overkill for this type of problem, and a simple reinstall is often not a very good solution to anything.

Walter & the sign out solution.
Probably a quick and simple trick if it works. The clear cache and site cookies suggestion in the second post of this thread is probably a more reliable method of doing of solving that sort of issue.

;-)

This reminds me of another Forum I was on.

Threads often had suggested solutions along the lines of

1. Uninstall browser A use browser B, that worked for me
2. Followed by another poster saying uninstall browser B use A

In fact the thread would be one where clearing cache and cookies would be the preferred solution. Uninstalling a browser and reinstalling a brand new instance of another has a similar effect to clearing cache and cookies, but is nowhere near as convenient.

I did try clearing the cache and cookies to no avail. I also tried the log out/in of yahoo. Thus, I did the reinstall.

It is possible that security software was blocking the attachments.

Did you remove personal data in case you uninstalled to force a new default profile?

I also can not open my attachments. All the suggestions given are Latin to me. I am not a computer tech. If I was I could fix it. I did reset Firefox and that did not help. Please help. Don't make me go back to IE.

Lincon,

The problem may relate more to your use of your chosen webmail service than to use of Firefox but we do try to help wherever possible.

Please start a new thread by asking your own question

1. use /questions/new <--clickable link
2. follow the prompts to provide troubleshooting information
   (You should come across a green button that helps by automating that process)
3. You may wish to post back in this thread to let us know you have done that.
   • this is a link back to this current thread /questions/978491
   • this is a link to all your posts https://support.mozilla.org/en-US/search?answered_by=LINCON&a=1&sortby...
     & for any questions https://support.mozilla.org/en-US/search?a=1&asked_by=LINCOLN&sortby=1&w=2
   • ANYONE more generally MINE