Retreiving fencearray failed

Iemand een idee wat dit betekend

See if the following site rings a bell:
Seems to be an API that keeps location of a mobile device. Possibly in use in an app somewhere?

It just means that OwnTracks cannot read a few files, which is to be expected when you just installed the app (and possibly even afterwards, I don’t know the specifics on when the app writes those files). You can safely ignore those messages.