As the thread you posted in was old I gave you your own and re-titled the post to be more obvious.
Whilst we have a resident technician who may spot this, it is a holiday so I can't guarantee him answering here.
Did you look in Recent Updates in Firefox Add-ons?
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Yep, checked recently updated, but not there. I'll check in with tech support after the holidays unless someone answers here. Thanks!
They may be open right now, where are you?
Please try below steps and post back the outcome
1. Open Add/Remove Programs and Uninstall "McAfee Safekey" from the list
2. Navigate to "safekey.mcafee.com" and login with your credentials.
3. Download the setup file and Install McAfee Safekey
4. Reboot PC and Open Internet Explorer - Enable Safekey Add-on and try logging in.
5. After logging on to Safekey in IE open Firefox and see if you are able to find the Safekey Add-on/Extension