Witchfix question

[Red Dog]

I try to make witchfix work to change some data in the Korean theater.
I downloaded Witchfix from PMC and unzipped it.

I select a blank .txt file
I select the korea.wch
And I hit the button ".wch===>text"
And all I receive is: Error reading the wch index file

I am sure I am doing something wrong. Can anybody know what?

Thanks for your help.
Red Dog