Game version: 5.0.14681.0
It happened like this: My prelate was holding a relic, being attacked by enemies. It entered the Aachen Chapel (probably) as it died. As a result, the relic got stuck inside the Chapel (as seen in the video) and neither could I put a prelate inside the Chapel, nor could I try to get the relic. Clicking the Chapel tasked the prelate to pick up the relic, which it couldn’t do since it couldn’t reach it. Basically, it denies you a relic and it renders your Chapel completely useless. Needless to say have this happen mid-game while enemies are amassing outside your base IS QUITE A BIT FRUSTRATING, since the game randomly decides gang up against you.
Since I know you won’t fix this soon, at least make a hotfix to add a “destroy landmark” button so a prelate can walk over and pick up the relic. Better than having to play without both the landmark and the relic.