I reinstalled the complete stuff and found, that without any maintenance the same error occurs with very small video files.
I worked with Steve's document 'Creatind a Video Editing Profile'.

Generally I think that each software should be able to be run in a normal computing environment. If there is a need to do very special thinks there must be something wrong with the software. Nevetheless I implemented most of Steve's suggestions, but that didn't help.
Therefore I want to come back to my 2 questions which remain unanswered until now:
1. How can I ask a question electronically to the support team? I have been able to ask a question but now I don't find a link where to do that.
2. What is the recommended maintenance and in which order must it be applied?
