I was unable to attach files in Outlook Web App. I using Edge on Win10 but for this particular reason, switched over to FireFox. That worked like a charm. For a month. Then stopped. Today. I checked and it allows pop-ups for the site. Not sure what else to do. I had to switch over to Gmail to send the attachment. Suggestions on things I can check?
I'm posting this under outlook.com as I don't see any more appropriate option.