I guess I'll have to wait.
Unable to drag and drop emails, tasks or attachments in Outlook - Microsoft Community

OMG!

Hi,
i've run into the same problem again! In china i released this update 1607 on accident and it updated 100 computers. No way i can rollback all of them. Some (not all) are having this same issue....

After many tests I resolved to rollback this update on all affected computers. This update is NOT ready.

Tks!

Hi There,
After Windows 10 aniversary update we are having problems on some computers where users are not able to drag 'n drop items (emails) to folders. If you click and move your mouse slowly...