Getting unknown device warning

Hi,
i'm very new to this field and trying to track few vehicles using this platform but no luck so far. i'm getting below error(found it in tracker-server.log) and any help would be appreciated.

2021-02-09 16:06:26  INFO: [44d4b800: gt06 < 5.35.166.137] HEX: 78781101086528204001555280330001007306230d0a
2021-02-09 16:06:26  WARN: Unknown device - 865282040015552 (5.35.166.137)
2021-02-09 16:06:36  INFO: [44d4b800: gt06 < 5.35.166.137] HEX: 787811010865282040015552803300010074729c0d0a
2021-02-09 16:06:36  WARN: Unknown device - 865282040015552 (5.35.166.137)
2021-02-09 16:06:46  INFO: [44d4b800: gt06 < 5.35.166.137] HEX: 78781101086528204001555280330001007563150d0a
2021-02-09 16:06:46  WARN: Unknown device - 865282040015552 (5.35.166.137)
2021-02-09 16:06:56  INFO: [44d4b800: gt06 < 5.35.166.137] HEX: 787811010865282040015552803300010076518e0d0a
2021-02-09 16:06:56  WARN: Unknown device - 865282040015552 (5.35.166.137)

Thanks
P!

You should probably read the documentation we have available on this website before asking on the forum.

hello Anton,
thanks for quick reply, I read the documentation and i couldn't figure what i'm doing wrong here.

Thanks!

OK, then what about the following documentation?

https://www.traccar.org/troubleshooting/

Hello Anton,
Thanks a lot for your quick help. End up delete and re add the device few times did it for me somehow.

Thanks
P!