Some icons are suddenly incorrect

I’m running latest UI5 on a Vera3. Suddenly some icons are incorrect and shows the general blue circle instead of the correct icon. Currently it’s the “Day or Night” plugin that have the incorrect icon.

I have cleared the browser cache and tried both Safari and Chrome. I have also tried to uninstall and install the plugin without any luck. When I click the wrench icon I can see a “broken image” flash before the blue circle appears again.

Yesterday the same problem occurred causing all the binary switch icons turning into blue circles. In that case the on/off control also disappeared. It was solved by restoring an old backup.

The problems might have started when including a Fibaro Flood Sensor.