Thanks for your answer, I found the problem right now.
I had the notification that a new Version is available and only rad:
The latest version of ESET Security Management Center (ESMC) is 7.0.72.0
Problem is solved right now.
I try to Update my ESMC Server (7.0.471.0) to the latest Version ( Latest version of ESET Security Management Center 7.x: 7.0.72.0 ) .
Update Server and Repository Server are set to 'AUTOSELECT' .
This Error appears : ' Failed to create task: The referenced repository package is not available'