transferred uml file does not render diagram

Hi there!

  I was wondering, if I do something wrong, or I just hit a bug. This is the situation: I connected to a DB, extracted DB model using diagrams->Show visualization; I saved the generated diagram and sent it to my colleague. When he tried to open, nothing was rendered. subsequent check showed idea deleted content of uml file, and displayed nothing. 

  any idea or hint?

Thanks in advance