I'm trying to use Remote Desktop to log onto a Dynamics 365 AOS server hosted in Azure, using the RDP file and credentials displayed on the environment's LCS page.
The Dynamics 365 AOS server is a Windows Server 2016 Datacenter Edition
box.
When accessing it via a Windows Server 2012 R2
server (i.e. RDPing onto the server, then downloading the DFO365 RDP file from LCS onto that machine and running the RDP client on the "proxy" server) all works, but attempting to access directly from my Windows 7 SP1
machine fails. A colleague, also running Windows 7 SP1
, has exactly the same issue.
My public IP (i.e. as seen by visiting WhatsMyIp) is whitelisted for RDP (via the LCS Maintain
> Enable Access
).
Both myself and my colleague had been able to RDP on to this VM until mid last week.
By going via the "proxy" server I was able to view the event logs on the remote Dynamics 365 AOS server. Looking at the Microsoft-Windows-RemoteDesktopServices-RdpCoreTS/Operational
event log I could see my connection attempts hitting this server, as there were warning messages stating: The server security layer detected an error (0x80090304) in the protocol stream and the client (Client IP:
123.45.67.89) has been disconnected.
(where 123.45.67.89 matches my public IP address). There are several other information events either side of the warning:
- info
The server accepted a new TCP connection from client 123.45.67.89:58177.
- info
Connection RDP-Tcp#4 created
- info
Interface method called: PrepareForAccept
- info
Interface method called: SendPolicyData
- info
PerfCounter session started with instance ID 4
- warn
The server security layer detected an error (0x80090304) in the protocol stream and the client (Client IP:123.45.67.89) has been disconnected.
- info
Interface method called: OnDisconnected
- info
The server has terminated main RDP connection with the client.
- info
During this connection, server has not sent data or graphics update for 0 seconds (Idle1: 0, Idle2: 0).
- info
Channel rdpinpt has been closed between the server and the client on transport tunnel: 0.
- info
Channel rdpcmd has been closed between the server and the client on transport tunnel: 0.
- info
Channel rdplic has been closed between the server and the client on transport tunnel: 0.
- info
The disconnect reason is 14
These events repeat 3 times, implying that MSTSC makes 3 connection attempts before reporting the failure.
Looking around the web I've seen mention of some certificate and key issues. I noticed that there are 120,078 files under C:\ProgramData\Microsoft\Crypto\RSA\MachineKeys
, including one beginning f686aace6942fb7f7ceb231212eef4a4_ (TSSecKeySet1). I haven't tried removing or amending any of these though, as don't know what the impact would be / haven't seen any explanation of why such fixes should work. My gut is that the sheer volume of files in that directory may be related to the issue.
Question
Does anyone know what may be blocking these connection attempts / what's required to allow the connections through?