Pixelmator images not showing in Xcode

For about 1 week I can't edit an image in Pixelmator, export it to JPG or PNG (probably also the rest) and use it for one of my iPhone applications.

• I still can use images which are not exported from Pixelmator


• Both real iPhone as simulator won't display the images


• They don't look different from other PNG or JPG's


• I can browse in the Project Navigator and the Storyboard of Xcode and see them but can't attach the images to UIImageViews via code.


• I deleted Pixelmator and re-downloaded it but nothing changed.

Help me please.