Decrypt message with java

Hello,

I would like to evaluate my smart meter data with Java.

I am currently trying to decrypt the data using a sample from the operator
(https://www.netz-noe.at/Download-(1)/Smart-Meter/218_9_SmartMeter_Kunde…)

For this I used the following code.
https://www.gurux.fi/Gurux.DLMS.Secure (AES-GCM-128 AES-GCM-128)

public class DecryptDlms {

public String hexData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
public String hexKey = "36C66639E48A8CA4D6BC8B282A793BBB";
public String hexSystemTitle = "4B464D6750000009";

public void decrypt() {

try {
GXReplyData rdData = new GXReplyData();
GXReplyData rdNotify = new GXReplyData();
GXByteBuffer bbData = new GXByteBuffer();

bbData.setHexString(this.hexData);

GXDLMSSecureClient sc = new GXDLMSSecureClient(true, 1, 1, Authentication.NONE, null, InterfaceType.WRAPPER);
sc.getCiphering().setSecurity(Security.ENCRYPTION);
sc.getCiphering().setSystemTitle(GXCommon.hexToBytes(this.hexSystemTitle));
sc.getCiphering().setBlockCipherKey(GXCommon.hexToBytes(this.hexKey));

System.out.println("sc.getData : " + sc.getData(bbData, rdData, rdNotify));

System.out.println("Notify - getErrorMessage : " + rdNotify.getErrorMessage());
System.out.println("Notify - getError : " + rdNotify.getError());
System.out.println("Notify - getData : " + rdNotify.getData());
System.out.println("Notify - getPacketLength : " + rdNotify.getPacketLength());
System.out.println("Notify - getCount : " + rdNotify.getCount());

} catch (InvalidKeyException | NoSuchAlgorithmException | NoSuchPaddingException | InvalidAlgorithmParameterException | IllegalBlockSizeException | BadPaddingException | SignatureException ex) {
Logger.getLogger(DecryptDlms.class.getName()).log(Level.SEVERE, null, ex);
}

}

}

Unfortunately I haven't received any feedback.

run:
sc.getData : false
Notify - getErrorMessage :
Notify - getError : 0
Notify - getData :
Notify - getPacketLength : 0
Notify - getCount : 0
BUILD SUCCESSFUL (total time: 0 seconds)

After many different attempts, I am now turning to you. Could you please help me here, where could my mistake be.

best regards