We are currently unable to logon to OWA and ECP. After entering our admin crendentials, we get an ERROR 500 on the browser. Looking at the Events for exchange, we see this error often:

Event ID: 2121

The Microsoft Exchange Replication service failed to start the TCP listener. Error: System.Net.Sockets.SocketException (0x80004005): An attempt was made to access a socket in a way forbidden by its access permissions
   at System.Net.Sockets.Socket.DoBind(EndPoint endPointSnapshot, SocketAddress socketAddress)
   at System.Net.Sockets.Socket.Bind(EndPoint localEP)
   at Microsoft.Exchange.Cluster.Replay.TcpListener.StartListening(Config cfg)

Following some guides out there, we have removed and created the OwaVirtualDirectory in Exchange Management Shell. Don't know where to go from here.

2 Answers 2


Exchange Server 2016 OWA Error 500 can occur due to the common error such as:

a) Powershell shortcuts get omitted. b) Virtual Directories c) Missing of Powershell DLL's d) OWA, ECP or Active sync do not work properly e) Missing of reference from the registry f) Issues with the certificate g) Improper operation or breakage of ASP.net

Reason Behind Error: Mismatch of canary tokens between the client and the Server is responsible for the generation of error 500.

How to get rid of Exchange Error 500: You can look out this link as needs to change in ADSIEDIT.msc to fix this issue.


An attempt was made to access a socket in a way forbidden by its access permissions

Looks like the port number that replication service is trying to start on is already in use.

Not an ideal solution but rebooting the Exchange Server 2016 might clear that up.

Did you try to find the port number on which it is trying to start and see if it is already in use and by what other service if so?

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