Cannot open bookmark (applicaton not found)

I cannot open any standard(mail, calendar, …) or personal bookmark.There are some similar threads to this issue (http://www-10.lotus.com/ldd/nd8forum.nsf/5f27803bba85d8e285256bf10054620d/41f0746346a1f66d852574ef000a1e97?OpenDocument or this: http://www-01.ibm.com/support/docview.wss?uid=swg21326290)

but I cannot find a solution.

I have reinstalled the client, deleted the bookmark.nsf, checked my reg-file for the correct Notes-path, … → no effect.

Does anybody have an idea?