WS-Security Encryption and Signature

Hello there,

I have got a problem to implement the Encryption and Signature.

I already created a client-keystore, client-truststore, server-keystore and server-truststore.
Imported the client-certificate into the server-truststore and vice versa.
I added the correct action parameters and encryptionPropFiles etc.
outProps.put("user", "clientx509v1");

outProps.put("passwordCallbackClass",
".... .client.UTPasswordCallback");

outProps.pu("encryptionUser", "serverx509v1");
outPropsput("encryptionPropFile", "etc/Client_Encrypt.properties");
outPropsput("encryptionKeyIdentifier", "IssuerSerial");
outPropsput("encryptionParts",
"{Element}{" + WSSE_NS + "}UsernameToken;"
+ "{Content}{http://schemas.xmlsoap.org/soap/envelope/}Body");
outPropsput("encryptionKeyTransportAlgorithm",
http://www.w3.org/2001/04/xmlenc#rsa-oaep-mgf1p");

outPropsput("signatureUser", "clientx509v1");
outPropsput("signaturePropFile", "etc/Client_Sign.properties");
outPropsput("signatureKeyIdentifier", "DirectReference");
outPropsput("signatureParts",
"{Element}{" + WSU_NS + "}Timestamp;"
+ "{Element}{http://schemas.xmlsoap.org/soap/envelope/}Body;");
outPropsput("signatureAlgorithm", "http://www.w3.org/2000/09/xmldsig#rsa-sha1");

Even after I was using the imported stores and property-files from the wssec_sign_enc example from apache-cxf,
The encryption and signature is still not working.
I am getting this excetion:
org.apache.wss4j.common.ext.WSSecurityException: The private key for the supplied alias does not exist in the keystore

So what can I do to find out what is missing? I am pretty sure I have exchanged the certificates or imported the keystores/property-files etc correctly.

Regards