I couldn't get it to add the images until I moved both the program folder and the images folder into the root of my hard drive. Probably something to do with the length of the folder path?
Leaving this here in case someone else has the same problem
Found another problem:
Images wont be added if the file names include "non-standard" characters such as accented vowels: á é í ó ú º â ê î ô û ª ä ë ï ö ü
