Up until sometime in the last few days, I was able to easily attach "Sales Lit" documents to emails in outlook with the Dynamics 365 Outlook App. You would start an email, click the "Dynamics 365" button in the ribbon, then select "Sales Lit", locate the attachment in the subject tree, and click "Add to Email". Then the file(s) you had uploaded inside of Dynamics 365 to a "Sales Literature" record would be attached to the email you were drafting.
However, people in my organization started complaining yesterday that they got a "download failed" error when doing this. I'm getting this error too, and if I save the email as a draft and reopen it, I get a list of errors for each attachment, each error reads: "An error occurred while updating permissions for '[FILENAME]'. Retry | Dismiss"
If it's a permissions thing, where would I change that? In security roles in Dynamics 365? Or Microsoft just up to something?
Error Screenshot # 1 "Download Failed" initial error
Error Screenshot # 2 "error while updating permissions..." looking at draft email
Found this fix that worked for me: What if you want Outlook 2016 to behave like Outlook 2013 and earlier? Well, the Attach File with the drop-down is not customizable directly, but you can add an old-style Attach File button. To do this, start a new email, right-click the toolbar, and click Customize the Ribbon. Right-click the New Mail Message section on the right and choose to Add a new group. Then select the Attach File command on the left, and the new group on the right, and click Add. I have called my new group Custom: http://www.itwriting.com/blog/9343-outlook-2016-attachment-mysteries-and-annoyances.html