Connection to server broken (ICM_HTTP_CONNECTION_BROKEN)

What causes this issue?

The server has closed the connection unexpectedly.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

The server has closed the connection unexpectedly. One possible reason
is that HTTP was sent to an HTTPS port (or another port that is intended
for a completely different protocol). In this case, ensure that you
address the correct port with the correct protocol. Otherwise the reason
for the terminated connection will have to be found on the server side.
Check whether the server has logged error messages on closing the
connection.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.