Achievements plugin

[MMFB]

heya i have installed achievements plugin today when when i click on custom achievements and create new and fill things choose image and save it says "Failed to copy the image of achievement." my images folder is writable what else i need to do :/ and if its possible to add links to that plugin instead of selecting image it will be good coz i already got images on my images folder of forums but i need to select them again from Computer and still doesent works help please