I believe the file you're dragging needs to end in ".txt" for XD to see it as a text file -- can you verify that?
If it does end in .txt, does dragging the same text file into a new, blank XD document do anything? Also, is the file stored on a network share or external drive or anything unusual like that?
Thank you for the quick response Peter.
Adding .txt to the end of the file name is the solution!
For some reason TextEdit didn't reformat from rtf to txt as it should have. OS X glitch maybe or perhaps TextEdit isn't the best tool to use.
Instead, I copied my list into word and saved it as in txt format and dropping this file (with the .txt) worked.
But just so you know, in the Create Design For Web And Mobile Apps tutorial, it does show the text file drop working WITHOUT the .txt extension.
Thanks again, you just saved me an hour of changing labels manually.
I am also quite new in XD and wanted to use the add .txt feature to populate a repeat grid of text boxes.
It works fine, when I'm making a repeat grid of a single text-box - the listed items appear as they are supposed to - but it does not work if i make a repeat-grid of a symbol (i.e. containing a frame, a picture and a text box)
SO if anybody is trying to use the drag .txt file to populate a repeat-grid of a symbol it probably will not work (as of dec. 1. 2017)
Thanks for sharing your experience. I was doing the same thing and ran into the issue. The text file reads only the first data and populates the first of the repeat grid element.
After reading your comment, I removed the text box from the Symbols gallery. Now when I use the file, it populates all the text fields! Yippee. Thanks again