Data not processed, errors in decoding

[JensHoRi]

While receiving redirected Data from Inverter, I got the following errors:

Jan 29 11:02:58 alderaan omnikloggerproxy.py[2726468]: omnikloggerproxy: Enabling MQTT forward to localhost
Jan 29 11:02:58 alderaan omnikloggerproxy.py[2726468]: omnikloggerproxy: Start in Omnik proxy server. Listening to 0.0.0.0:10004
Jan 29 11:02:58 alderaan omnikloggerproxy.py[2726468]: omnikloggerproxy: MQTT connected
Jan 29 11:03:58 alderaan omnikloggerproxy.py[2726468]: omnikloggerproxy: Ignoring received data!
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: ----------------------------------------
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: Exception occurred during processing of request from ('10.xxx.xxx.xxx', 22352)
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: Traceback (most recent call last):
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: File "/usr/lib/python3.10/socketserver.py", line 316, in _handle_request_noblock
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: self.process_request(request, client_address)
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: File "/usr/lib/python3.10/socketserver.py", line 347, in process_request
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: self.finish_request(request, client_address)
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: File "/usr/lib/python3.10/socketserver.py", line 360, in finish_request
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: self.RequestHandlerClass(request, client_address, self)
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: File "/usr/lib/python3.10/socketserver.py", line 747, in init
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: self.handle()
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: File "/usr/local/bin/omnikloggerproxy.py", line 99, in handle
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: self._processmsg(msg)
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: File "/usr/local/bin/omnikloggerproxy.py", line 102, in _processmsg
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: rawserial = str(msg[15:31].decode())
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: UnicodeDecodeError: 'utf-8' codec can't decode byte 0x81 in position 1: invalid start byte
Jan 29 11:04:40 alderaan omnikloggerproxy.py[2726468]: ----------------------------------------

Here my Config:

omnikdatalogger:
proxy:
loglevel: INFO
listenaddress: 0.0.0.0
listenport: 10004
serialnumber:
- 410xxxxxxx
- 415xxxxxxx
- 411xxxxxxx
omniklogger: 127.0.0.1
omnikloggerport: 10002
output.mqtt:
# mqtt integration
# Creates sensor 'binary_sensor.datalogger' with MQTT auto discovery in Home Assistant
#
discovery_prefix: omnikdatalogger
host: localhost
port: 1883
retain: true
client_name_prefix: ha-mqtt-omniklogger
username: xxxxxxx
password: xxxxxxxx
device_name: Datalogger Proxy
append_plant_id: false
# Sensor name (omnikproxylogger only)
logger_sensor_name: Datalogger

I have no idea