Why can't I edit a .txt text file?
 

I am probably not seeing something obvious. I pulled in a few .txt files ( straight forward ascii files). I can view them ok, but can't edit them. What am I doing wrong?

check if .txt is in
Options -> Editor -> File extension to display in text editor

If you stored the document in UR, you should be able to edit it internally. Documents that are linked instead of stored aren't editable within UR (use Ctrl+J or Ctrl+E to edit externally).

Aha. This is what I expected I was able to do (since I can do so with a linked Word document). I don't do much editing in UR but this is a pity. Linking is very useful for me. Thanks for the answer.