Vim command S is missing

Question

In Vim I once was able to select multiple lines with v, and then press S to replace all those lines and directly go to insert mode.

However, when I now press these buttons, nothing happens. How can I get that behavior back?

Answer 1

There is a possibility that you have the Surround plugin installed which uses S and s.

Alternatively, you can use c for the same effect.

Answer 2

S and s should be working for you.

A good place to start troubleshooting is to see what the following command shows you:

:verbose vmap S