This is affecting all users in our organization. If we have received an e-mail in plain text with an attachment, and attempt to forward that e-mail, Outlook strips the attachment. It started today after Tuesday's updates. The default option under "compose messages in this format" is set to HTML, but I have tried all options. The attachment is immediately stripped after hitting the forward button. If I go to Format Text on the forward, and change to HTML or Rich Text, it does not appear. If I send the e-mail, the recipient does not have an attachment.
I have tried starting Outlook in safe mode, disabling various add-ins, repair installation, to no avail.