It's really tough getting the path right. The best workaround is just to put the images loose in the same folder as the InDesign file.
Your path needs to use a colon instead of a forward slash. Also you might need to add the name of your hard drive before Users.
The easiest way to get the correct path is to manually place one of the images, then go to the links panel, right-click on the image name and select Copy Info > Copy Platform Style Path.
I always put the csv file into the same folder as the images.
Thanks a lot to everyone!
I just put the source file in the same folder as the indesign file and everything worked!