import error in package history of iTunes Producer

I can't update the book via iTunes Producer. After successful submit operation via iTunes Producer, I have received import error in package history pane. I contacted to Apple support, they said there is a problem with one of the hype widget. Support response;

"The error is due to one of the Hype Widgets. Based on the Import Error it looks like unsupported characters in the assets inside the Widget itself. Unicode normalization problem on file names inside the EPUB. So change all the asset name listed below

 assets/widgets/genel_çözüm.wdgt/genel_çözüm.wdgt.hyperesources/Asset4_2x.png,

assets/widgets/genel_çözüm.wdgt/genel_çözüm.wdgt.hyperesources/Asset5_2x.png,

assets/widgets/genel_çözüm.wdgt/genel_çözüm.wdgt.hyperesources/Asset6_2x.png,

"

I completely replaced the widget with an image viewer. But received import error again. I would be happy if someone helps me about this error.