For some time now, a lot of Mac’s with Microsoft programs have been crashing. Check with Microsoft / Mac support sites.

I've called the big guys to help you. Good luck.

It is just with FireFox that it is not displaying the box to select my certificate. It is displaying for most of the others sites but this one. It works with Safari however Safari will not let me insert an attachment.

 Thank you for bring in the "Call for Fire".

You can try to rename the cert8.db file (cert8.db.old) and delete the cert_override.txt file in the Firefox profile folder to remove intermediate certificates and exceptions that Firefox has stored.

If that has helped to solve the problem then you can remove the renamed cert8.db.old file. Otherwise you can rename (or copy) the cert8.db.old file to cert8.db to restore the previously stored intermediate certificates. Firefox will automatically store intermediate certificates when you visit websites that send such a certificate.

If that didn't help then remove or rename secmod.db (secmod.db.old) as well.

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

• Help > Troubleshooting Information > Profile Directory: Show in Finder (Windows: Show Folder; Linux: Open Directory)
• http://kb.mozillazine.org/Profile_folder_-_Firefox

Neither option of renaming the .db files worked. It is asking for the PIN to unlock the keychain but it is not coming back afterwards to let me select the certificate.

 This is just odd that it is happening in FireFox when this was the only one that I could get this to work on a MAC.  

 I am still attempting other trials to get this to work.

I'll report back if I find something that did work. Until then keep the ideas coming.