Hi Bernd
I recommend to check following 2 points.
1)Make sure your connector instance include dashboard application.
If you go to connector setting, you may see the connector instance BPM_ACube_default.
To use Analytics information in BPO dashboard, please make your this instance has
appliction ANALYTICS and BPO Dashboard.
If the setting only contain ANALYTICS, then you need to include BPO dashboard
in application setting.
2)Make sure your SolMan has Note 1801801 (latest version 38) and 1806818 (latest version 37).
Best Regards
Keiji Mishima