Is it possible that the file the company gave you is for the CS3 version? There are differences between CS3 and CS4.
You could send me the text file directly--my email address is under my user name.
I am dealing with the exact same error message. Olav, were you ever able to find a solution?
I didn't find a problem, so I haven't found a solution. Questions to start with:
Which version of InDesign are you using?
Which scripting language are you using?
Have you edited the FindChangeByList.txt file?
I started another thread on this topic which you also replied to. Perhaps we should just finish the discussion there?