The connection with the server was terminated abnormally

[TerryO]

I’m getting this error every time I try to send a transaction to my sandbox account: “The connection with the server was terminated abnormally”. The server is not using TLS 1.0 or 1.1 and when I use the production server with a test CC number it is sending back the invalid card message so it is working on the production server but not the sandbox. The sandbox should be sending a test approval response back.

Anyone have any ideas why this could be happening?

[Aaron]

For regular 2008 (not R2), Microsoft has just released a patch to enable TLS 1.2:

https://blogs.microsoft.com/microsoftsecure/2017/07/20/tls-1-2-support-added-to-windows-server-2008/

[TerryO]

It was 2008 R2 but the patches didn't work - TLS 1.0 was still showing up (enabled) at AN's sandbox server. We abandoned the 2008 server, installed the site on a 2012 server and all is OK now - AN sandbox sees only TLS 1.2 now.

Not sure why. The patch didn't work but maybe the manual registry edits in the Microsofts pubs (referenced in an earlier post) would have - we didn't try that, just the downloaded patch install. When that didn't work, we just moved the site to a 2012 server. (Hate messing with the registry on a server.)