I recently tried a seed that should have had a woodland mansion close to spawn, but after looking for it for several hours, I gave up and used
/locate. It gave me coordinates that fit what I saw in the seed showcase, but the mansion was most definitely not there.
I went into spectator mode and found a large mineshaft right below (which was also mentioned in the seed video; everything but the mansion lined up) but when I tried
/locate Mineshaft I got coordinates extremely far away.
I have used locate successfully in other worlds without re-launching minecraft, and I was definitely in 1.11 every time I loaded this world. Other than this oddity the world doesn't seem corrupt or anything.
Am I somehow using
/locate wrong? Or is this a problem with
/locate/my world/both? Is it relevant that I was on peaceful difficulty?