Don't open library and ebook

Latest version ADE, perfect workingly until 2 months ago, now when I open ADE I have just white screen , lazy reaction and it's impossible to load new ebook. The message is "this ebook already present in your library", but for me it's impossible to see it...

I delete authorization, delete and reinstall ADE but nothing change....

With anothe machine (older) everything work...

Somebody has an idea ?

Thank you so much, 

Cristiano