[MC-44904] Mobs Can Spawn With The Same UUID As Other Mobs In World

I Used The Command

/summon Zombie ~ ~ ~ {UUID:11111111-1111-1111-1111-111111111111}

And A Zombie With That UUID Was There, But When I Summoned Multiple And Used /kill @e[type=zombie] It Only Killed One, And In The Console It Sayed IT Killed All Of Them. When You Type /kill @e[type=zombie] Again, It Will Say 'Could Not Find Entity' A Bunch Of Times.These Are Not Ghost Mobs, And They Will Attack, Deal Damage,And Get Hurt By Anything.

Linked issues

is duplicated by 2

MC-55603 Error message: That entity cannot be found/ Mobs with same UUIDs Resolved

MC-93994 Game only targets one entity when more than one have the same UUID Resolved

relates to 1

MC-86082 Cannot summon an entity with a custom UUID Resolved

Attachments

Comments 20

CubeTheThird 2014-01-14T20:42:56Z

Please do not mark unreleased versions (anything starting with "Future Version") as affected. You don't have access to them yet.
Also, are you certain these other zombies weren't assigned other UUIDs, considering they are supposed to be unique?

Joshua cooper 2014-01-16T16:25:37Z

Yes, There At The Same UUID, Because The [UUID] Test Works for Testfor / Tp ect

Jeuv 2014-01-16T16:49:27Z

Still in 14w03b.

Nathan Adams 2014-01-16T17:41:59Z

The bug here is that you had multiple entities with the same UUID, not that you couldn't kill them. There should only be one entity per UUID.

Jeuv 2014-01-16T17:45:37Z

Can't you just make it that there can only be one entity per UUID?

10 more comments

kumasasa 2014-03-02T08:53:51Z

Can't you just make it that there can only be one entity per UUID?

What do you expect the game to do if you summon an entity with the explicite tag UUID:11111111-1111-1111-1111-111111111111 ?

Joshua cooper 2014-03-02T10:17:03Z

The problem is the fact that you are able to summon an entity with the same UUID as others, causing various glitches. This could be a problem if you summon a mob with the uuid of 12345678-1234-1234-1234-123456789123, and there is a mob already with that uuid, then it could potentially corrupt your world ( has happened )

kumasasa 2014-03-02T10:20:06Z

Sure, but again the question, what do you expect the game to do in that situation ?

Joshua cooper 2014-03-02T11:54:37Z

to have a message saying "UUID Already being used" or something.

matthias 2015-03-13T04:04:32Z

yes it is i can spawn 2 mobs with the same uuid in 1.8.3 and i can only reference the first one until i exit(or restart server) my world

matthias 2015-03-13T04:15:19Z

if i spawn 2 zombies in the nether then try to kill both of them only one will die but the console will say that 2 have been killed if i then exit the nether and enter again i can kill him

matthias 2015-03-13T04:38:06Z

i can kill them with weapons but anything that references uuid will not work unless i kill one then exit the world then reenter it and kill the other with commands

Anon Ymus 2015-08-15T02:14:48Z

Unable to reproduce.

matthias 2015-08-25T04:45:08Z

i can summon a zombie with the same uuid and cant kill both of them with the /kill command

matthias 2015-08-25T04:47:17Z

if the zombie still exists this error happens when /kill is used

matthias 2015-08-25T05:08:41Z

this error is fixed in 15w31c by making summon check if it can summon a mob with that uuid and will respond with:"Unable to summon object" if a mob with that uuid already exists.

CubeTheThird 2015-08-25T18:23:19Z

UUIDs can no longer be specified via commands (it is now ignored).

[Mod] redstonehelper 2015-08-25T18:28:19Z

Not quite true, see Searge's comment on MC-86082.

Torabi 2015-11-29T19:28:54Z

UUIDs are now truly unique. It's no longer possible to spawn an entity with a particular UUID if one already exists with that UUID. I believe this was fixed in one of the early snapshots, though I'm not sure which one.

matthias 2015-11-29T20:00:56Z

The UUID nbt tag is no longer parsed check MC-86082, Sarge commented there. It is fixed in version 33c.