There is Sharded collection named: "Users". I do following for UnShardig Users.

1. sh.stopBalancer()
2. moving all chucks to Primary shard
3. config : db.collections.remove(

{ _id : collection }

)
4. config : db.chunks.remove(

{ ns : collection }

)
5. db.adminCommand("flushRouterConfig")

https://jira.mongodb.org/browse/SERVER-9845

every thing seems good. but when i get db.Users.stats() it throw error :

Sun Mar 9 11:11:54.216 error:

{ "$err" : "stale config on lazy receive :: caused by :: $err: \"[MyDB.Users] shard version not ok in Client::Context: this shard contains versioned chunks for MyDB.Users, but no version set in request...\" ( ns : MyDB.Users, received : 0|0||000000000000000000000000, wanted : 4|0||531c198cc654610530a5f373, recv )", "code" : 9996 }

at src/mongo/shell/query.js:128

and finally after I restart Primary shard, up error disapear.

Do I missed something? or it's mongodb bug?