It experienced this issue(error:86) today(Oct.17 1PM, GMT+9). I worked it a few days ago. It worked at that time. Also, this problem occur only with a specific file. I reinstalled the Creative Cloud, and xd. And I did download log collector but I have got the same error. I did almost everything to fix this problem. But I have still same problem.
we are sorry that you are experiencing problems with Adobe XD. We will do our best to help you. Thank you for giving us so much information. I found this thread with a similar problem to yours, I suggest you take a look at it, it might help you: Unable to open the local file in XD getting (Error:86)