Hello @RainerH,
Thank you for reaching out to the Community! I apologize that you are having this experience. Can you please email social_support(at)constantcontact(dot)com with the title of the email you are working on, the name of the image that this is happening to located in your library, your username, a reference to this post, and a screenshot of the issue so we can do additional research on why this might be happening? Thank you!