New error after connection had been working

[AMLF-AAB]

Our users use the OwnTracks app to send location data in to our system, and it's worked brilliantly so far. But one of our Android users, whose location had been received via the API no problem, suddenly started getting error notifications. The first error he received was:
"Error: java.net.UnknownHostException: Unable to resolve host "[host name]": No address associated with hostname"

We confirmed that his URL endpoint was set correctly, and no other users are having this issue.

He has rebooted his phone, and that error disappeared, but was replaced by one which simply read "Error"

Nothing is coming through from his OwnTracks to us since these error notifications started.

Advice gratefully received!

[jpmens]

Unable to resolve host "[host name]": No address associated with hostname" is definitely a host resolution (i.e. DNS) issue; the app wasn't able, at that point in time, to have look up the address of the URL you specified in the app.

replaced by one which simply read "Error"

I am not aware where in our code it would say that, and i very much doubt it actually is a message from OwnTracks.

[jpmens]

Our users use the OwnTracks app to send location data in to our system

Out of interest and curiousity: can you tell us a bit more about this system and the number of users? We're always looking for new use-cases. :-)