When try to open attached document with a password on it. shows message "Document cannot be downloaded"

A pdf document is attached to an email and the document is protected by a password. When I select Open a message "File cannot be downloaded " is shown

I have a similar problem. Sometimes you may have to try, try, try, again and eventually it will (maybe) download. I can download bigger files elsewhere ok so I don’t think it’s my computer or modem. It’s just emc attachments that are a problem - anything over 250kb can be a problem. I don’t even try to download attachments over 5Mb even with common extensions like mp4 etc.