Fatal error when user entity is saving

I ran into another error when I tried to upload an image through an image field which is attached to my users' accounts. Doing this gives me a white screen and the following message:

Fatal error: Cannot access empty property in [...]/sites/all/modules/fe_paths/fe_paths.module on line 149

Edit: The image field was added and had an image file stored in it before I installed File Entity Paths. I just wanted to replace the image, which image fields offer you to do. To check if this might have been the problem I also added another image field to the user accounts and tried to upload a new image using the new image fields. The new image field wouldn't give me the error, but it would also not store the image. After reloading the page the field is empty again.

Is it possible that File Entity Paths conflicts with the integration of image fields? As far as I can tell, everything works fine with file fields.