Moving the last chunk away from a shard, then back onto that shard, and trying to split it will cause an error. The chunk is still split though. The split does not appear in the changelog however.

Error:

{
	"cause" : {
		"errmsg" : "exception: couldn't find chunk { _id: MinKey }->{ _id: MaxKey }",
		"code" : 13586,
		"ok" : 0
	},
	"ok" : 0,
	"errmsg" : "split failed"
}

jstest attached.

The test fails in all mentioned affected versions. In 2.5.4 it succeeds without failure.