I found this problem with dropbox folder aliases, but regular folder aliases sometimes too. I found if I open ther folder, I could drag and drop into the window. I also found that making a new alias of teh original folder was the key.
We love to learn from the educators who use Dropbox. Whether you teach kids, teens, adults or a combination of all three, we want to know what apps and integrations you use with Dropbox to help with teaching. Which of the ones below is your favorite, or most used tool?