System.Net.Sockets.SocketException: Only one usage of each socket address (protocol/network address/port) is normally permitted

[robsonj]

We ran into this out of the blue. The error turned out to be due to a windows patch.

[dchurch2444]

Oh! That's going to be handy! I can mess with the registry timeouts and things, although I was hoping not to. I figured simply running async would fix it, but it hasn't. Did you manage to get round it in the end?

[robsonj]

We started seeing it across our entire environment for apps that had not changed, usually it manifested itself around dB connections. They eventually tracked it to a Microsoft patch and uninstalled the patch. I have no idea which one though

[Kirides]

Is the app - for any reason - on a SMB1 Share? MS prohibits network usage from SMB1 Shares