irules - data group list - external file getting binary character error - any ideas what may be causing error message?

I believe the file contains tab characters, which are known to trigger this error.

 

 

I loaded into TextPad and hit the right-arrow key, observing as I went along. You should be able to see this in Notepad as well, but don't use WordPad or anything else that inserts its own invisible formatting characters as you'll only make matters worse.