I have been rying to control an airport that I have not personally controlled before.
After searching and finding the airport in the search box and clicking on the found airport name in the list, when clicking on the "Download Scenery" button an error box comes up saying "Error while downloading scenery for airport [ICAO CODE]! (Server responded with error 403 Forbidden)"
This then leaves the tried name in the list of known airports after restarts, and OpenRadar is unable to delete it with the "Delete Airport" button. You have to go through the folders and manually delete the affected airport folder to remove from the list of known airports.
Seems like the map source (Open Street Map??) that is used for OpenRadar has moved or had settings / security changed or added. Finding a new map loading source for OpenStreetMap would be needed to restore functionality.