Hi Helmut,
Please check below Blog and KBA:
Incident Management and Change Request Management: E-Mail functionality in SAP Solution Manager 7.1
http://scn.sap.com/docs/DOC-35291
1831361 - Solution Manager - Changing status in CRM_UI gives BSP error
Exception Class - CX_SY_DYN_CALL_PARAM_MISSING
Thanks
Vikram