Task Attachments Disappearing

Hello, 

I attach emails to To-Do tasks by creating the task, opening it, and dragging and dropping emails into the Add Files section of the task. Over the last several weeks, when I go back to one of these tasks I receive an error that says:

"We're Sorry! There was an error uploading (MESSAGE NAME).msg, please try again later."

When I click OK, it returns me to the task but the attachment is gone. This is obviously a problem because I don't want to have to go back and search my email, that is the point. 

This same issue has also occurred when an email is added as a link attachment by dragging into Outlook tasks. The attachment shows up in To-Do as a link, and when you click it you get to a blank website instead of taking you to the message in Outlook online. 

Several others in our company have been experiencing this issue.