Hi there. Thank you for your comment. I installed all 3 jdk's offered with Leap 15.0 java-1_8_0... java-10... java-11... The result is always the same. The Notes client chrashes with the same error message when starting. On Leap 42.3 I use java-1_8_0... and the Notes Client is running as it should. Do you have any other idea, what I can do?