Creates multiple images and only one works

Does the plugin create several images in my media file. After starting to use this plugin all the pictures I have uploaded have three to four versions in my media directory. I disabled this plugin now, and new problem arose.

Now I deleted some of the duplicates, and left the version that actually says that it is linked with a post. Still those images were deleted from the linked post, so I guess the one marked was not the one really in the post. But now if I try to add the copy of the image I left in the media directory, it still shows as blank on front-end.