I've attempted the seemingly foolproof method of destroying a system with planet crackers to get rid of the Umbral Choir sanctuaries that were present there. The sanctuaries somehow survived and shown no signs of going away after some turns passed, so I used ground forces to conquer the now inhospitable system the old fashioned way - but after the battle was finished, instead of showing me a battle report, the game zoomed in unnaturally close on the system and stopped responding to ALL inputs, including Escape and the mouse. The only way to close the game was via task tab or task manager.

Are UC sanctuaries meant to survive on destroyed worlds? Did any other fan of planetary-scaled explosive solutions also experience this issue, or were your wreckage-system invasions successful? Most importantly, do sanctuaries in destroyed systems give any benefit to the Choir?