You think nobody is gonna ask you about your config for firebase?
The problem is that you had firebase/web notifications configured and then you disabled those option in the configuration file. This is the result. You either have to re-enable them in the config or remove those notifications.
Thanks Anton and Track-trace for the reply, actually I had a traccar setup originally, now I have installed it on another server but connected to the same database, here I have not configured anything for notification, now am facing that error, how exactly I should deal with this.
Thanks again!
I believe I already answered the question. There are two options I mentioned in the previous comment.
the device is connecting and disconnecting