In relation with bug  MSI installer should kill jEdit server first
Here is a patch to connect to a running jedit server and ask it to exit, before performing install.
Code to connect to the server is taken from jEdit.java.
If there is a running instance of jEdit, with -noserver
option, it doesn't see it. But then, the user can close it easily.
This patch assumes that Progress.java has been updated as per [jedit-Patches-2327736]