eBooks do not open after progress bar and 4.5.11 freezes

Hi evervyone,

after implementing an eBook to Adobe Digital Editions 4.5.11, the book does not open after the progress bar ended. Afterwards, the software freezes. After reopening the software, sometime the eBook is not shown in the list. In case it appears in the list, I have to download it again, the progress bar starts again and the eBook does not open in the end and the programm freezes.

Same happened after deinstalling 4.5.11 and installing 3.0. I also tried in both versione to rename the folder "My Digital Editions" - no effect.

Thank you for your help!