Is LabVIEW and Office both German? Under Control Panel >> Regional Options >> General, is the language set to German? How about under Regional Options >> Input Locale? Reboot if you make any changes.
I would suggest reregistering the nireports.dll. It is located in the National Instruments\Shared\NI Reports directory.
http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/4f811a9b23f1d46e862566f700615b7a?OpenDocument
Next, mass compile (Tools >> Advanced >> Mass Compile...) the LLB's in the
\vi.lib\addons\_office