WARN???

hello, reading the log file I found errors that I do not understand. please help me understand them.

2023-05-12 00:00:01  WARN: [48d9206d] error - Log file renaming failed - RuntimeException (Log:71 < ... < StandardLoggingHandler:84 < *:56 < *:42 < ... < NetworkMessageHandler:37 < ...)
2023-05-12 00:00:01  INFO: [48d9206d] disconnected

2023-05-12 00:00:09  WARN: [188efc16] error - Connection reset by peer - IOException (...)
2023-05-12 00:00:09  INFO: [188efc16] disconnected

2023-05-12 00:00:39  WARN: [25617e9a] error - Connection reset by peer - IOException (...)
2023-05-12 00:00:39  INFO: [25617e9a] disconnected

2023-05-12 00:01:30  WARN: [603c9bf8] error - begin 21, end 24, length 4 - StringIndexOutOfBoundsException (... < Gps103ProtocolDecoder:413 < ExtendedObjectDecoder:52 < ... < WrapperContext:102 < ...)
2023-05-12 00:01:30  INFO: [603c9bf8] disconnected

First one might be no write acces to that directory or no space.
error - Log file renaming failed

Second one might be port scan or something else then your device connecting on that port.
For that you need to show the Hex from log.

"Connection reset by peer" can be anything. It just means that a network connection was closed by reset.

thank you for all the efforts you make to help us use traccar

and this message ??

2023-05-12 00:01:30  INFO: [603c9bf8] connected
2023-05-12 00:01:30  INFO: [603c9bf8: gps103 < 154.121.53.177] HEX: a503003b00008921301416224482292f33303346473836383136363035333630303233350000000000000000000000000000000000000000000000303330334647e6
2023-05-12 00:01:30  WARN: [603c9bf8] error - begin 21, end 24, length 4 - StringIndexOutOfBoundsException (... < Gps103ProtocolDecoder:413 < ExtendedObjectDecoder:52 < ... < WrapperContext:102 < ...)
2023-05-12 00:01:30  INFO: [603c9bf8] disconnected

That's a wrong protocol, so you get this error.