Is the problem on Microsoft's consumer version of Outlook (live.com) or on a company "Outlook Web App" site?

If the site is giving you a specific error message, could you let us have the wording? Or if it's easier, you could attach a screen shot to a reply. (Please blur out any personal/confidential info.) This article has tips on that: How do I create a screenshot of my problem?

Its consumer version of Outlook. See image of screen error message.

I'm a little confused as to why it thinks it is inserting a picture... That is a completely separate line on the Insert menu.

When I insert a PDF, I get a generic icon (looks like a book on an orange background). Maybe the site is having a problem with that image??

Could you try this generic suggestion in case you have some some out-of-sync cached files or old cookies. Make sure to save your draft message first.

When you have a problem with one particular site, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site.

(1) Bypass Firefox's Cache

Use Ctrl+Shift+r to reload the page fresh from the server.

Alternately, you also can clear Firefox's cache completely using:

orange Firefox button (or Tools menu) > Options > Advanced

On the Network mini-tab > Cached Web Content : "Clear Now"

If you have a large hard drive, this might take a few minutes.

(2) Remove the site's cookies (save any pending work first). While viewing a page on the site, try either:

• right-click and choose View Page Info > Security > "View Cookies"
• Alt+t (open the classic Tools menu) > Page Info > Security > "View Cookies"

In the dialog that opens, you can remove the site's cookies individually.

Then try reloading the page. Does that help?

Thanks for your efforts but nothing works. I have cleaned out cookies, even restored computer to a date before this started with no success. Surely I cannot be the only one with this issue. I can attach word, photo, rtf, files but not pdf.

As jscher2000 said above, I wonder why it's thinking your trying to attach a pic; when I click on files as attachments that are PDF I get the same brownish orange icon once downloaded. Perhaps the file you're trying to attach is corrupted. However, you might try t0 uninstall ADOBE Acrobat and reinstall ensuring you have the most uptodate version.

Already tried that. I have tried with numerous files so it can't be just a corrupted file.

Should I uninstall then reinstall Mozilla? If I do will I loose all my bookmarks etc.

Reinstalling Mozilla to its default might be helpful. It will save your bookmarks and also set up a folder on your desktop of the old FF data.

You can experiment with how Firefox would run after a reset or reinstall by creating a new profile.

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 have completely fresh settings databases and a fresh cache folder.

Exit Firefox and start up in the Profile Manager using Start > search box (or Run):

firefox.exe -P

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

You'll click the Create Profile button. I recommend using the default location suggested (in other words, don't click the button to choose a different folder). Then start Firefox in the new profile you created.

After Firefox settles down, try Outlook. Any luck?

If it works, log out of Outlook, exit Firefox, restart it and check again. If it doesn't work the second time, one possible explanation is a a system-installed add-on getting picked up or activated.

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 was just about to reload firefox and decided to reboot one more time. And now for no particular reason it is functioning normally again. Thanks for your efforts.

u r welcome! stranger things have happened...:-)

Worked for two days and now it doesn't again. Does anyone lse share this problem? It there a fix? Thanks

Could you try the new profile test? https://support.mozilla.org/questions/993180#answer-553391