I’ve seen this happen before 3 or 4 times when a user just closes their session instead of logging out of it. Please try the things in the KB article above under JohnThePro’s answer.
May be a bit late but this worked for me, credit to Elton Saul. Create the DWORD below and set to 10000 My next task is to find out why it has outstanding connections 🙂 https://social.technet.microsoft.com/Forums/en-US/e1d60cc0-0096-4859-a0e7-eb7f11905737/remote-desktop-v10-error-0x4-from-mac?forum=winRDc A temporary workaround for this issue is to increase the maximum outstanding connections limit. On client SKUs it is … Read more