S/MIME controls are not available

Emails that have been signed and or encrypted will display the message "S/MIME controls are not available". This message means that when OWA tried to load its S/MIME plug-in that allows for signing, encrypted, and decrypting of emails, something went wrong and failed to load the plug-in. The only web browser that is capable of loading this plug-in is Internet Explorer on Windows. No other Windows or Mac web browser is capable of loading this plug-in, therefore you will not be able to sign, encrypt, or decrypt email. Emails that have been signed can still be viewed and replied to, but emails that are encrypted cannot.