title: Custom Grafana panels greyed out
body: <p>I wrote an exporter to export my statistics to Prometheus and then I created some simple graphs in Grafan for them. When I create a graph they are working but as soon as I save and close the dashboard and open it again all the graphs/panels greyed out (as it can be seen). I checked the logs of Grafana but there is no log related to this. What is the problem or at least how I can debug this?
  <a href="https://i.stack.imgur.com/tOdRc.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/tOdRc.png" alt="enter image description here"></a></p>