To help to see what’s happening when we drop the clip on something, we can put an editable text box off stage on the main movie timeline. When you’ve created your text box, make sure you name it ‘debug’ using the variable field in the  Text Field properties box, Modify>Text Field. It’s not essential that we do this, but I find it helps with debugging.

Test the movie. You should see when the clip is dropped that the text field is given the value of the clip’s _droptarget property. If not, check your ‘debug’ box is on the main movie timeline and not contained in a movie clip. You may need to temporarily increase the movie size (Modify>Movie>Increase Height) to see the textfield.