Looking for help with ExtendScript Toolkit.

I am using ExtendScript Toolkit 4.0.0.1 on a Mac with system 10.10.5. It goes into the spinning beachball often when I drag to select text or click to place the insertion point somewhere else in the code. There is some hesitation when I type in it. When I looked for a newer version it says the most recent version is 3.8.

What is the real up to date version? Where can I get it? Is there a way to unfreeze the app? Command-. doesn't help.