Ok. Now I know what's my error. I thought that I have the 4 private keys active, memo, posting and owner. I thought my password is missing. But: I do have the password and only the three private keys active, memo and posting. I don't know my owner private key, because it is not shown in the Steemit wallet. I think it is genarated automatically if I enter my password in Steemit.

Ist there a way to get the private owner key?