[MC-69720] Nether Fortress generation problem

For some reason a new survival world i created in the 1.8-pre2 snapshot did not spawn chests or blaze spawners in an entire nether fortress. However, when i created a creative world to see if the same thing happened the fortress spawned like normal with chests and blaze spawners. I do not know if it was just a world generation problem or if it is a bug. Thought I might as well bring it to mojang's attention. The attached picture shows where a spawner should be. (No, i did not mine ouut the spawner)

Linked issues

is duplicated by 3

MC-93051 Missing Blaze Spawner in Nether Fortress Resolved

MC-104562 1.10 Nether fortresses do not have blaze spawners. Resolved

MC-107367 No Blaze Spawners Resolved

Attachments

Comments 17

pneuma 2014-08-28T09:38:45Z

Can not reproduce.
See 2014-08-28_18.36.10.png
seed: -2440829289729171825
x:-849 y:77 z:-905

kumasasa 2014-09-01T12:34:31Z

Please provide seed and coordinates.

Jonas Albrektsson 2014-10-25T14:09:00Z

I don't know if this is related but i experienced the same thing.
Because of the glowstone bug MC-49126 we deleted the entire Nether (the DIM-1 folder).
When it regenerated the terrain the spawners where missing.

Seed: 5422167314822212631
Coords for spawner: x:-396 y:76 z:-136

B R 2014-10-27T00:37:52Z

I am experiencing this problem in 1.8.1 pre-releases 2 and 3. I didn't test pre-release 1, but the problem was not occurring in 1.8.0. No monster spawners or chests generate in the fortresses. Example: seed=-3320457680109975269, coordinates=(351x, 55y, 187z); (394x, 55y, 174z).

B R 2014-11-07T00:47:25Z

I've tried a few tests now. On the same computer, with the same version of Java, using the same seed and visiting the same coordinates, on any of the pre-releases, and in single player or on a server, I cannot reproduce this bug in a newly generated world. However, on the server where I first experienced it, it keeps happening not matter how many times I delete and regenerate the chunks. I don't know what to make of that.

7 more comments

kumasasa 2014-11-07T06:50:51Z

@@unknown: Did you update the second server to 1.8.1-pre4 ?

B R 2014-11-07T23:47:48Z

Yes. On 1.8.1-pre4, if I create a new world in single player or on a server with the seed I gave and at the coordinates I gave, the spawners and chests appear. But if I take my existing world and delete those chunks or even the entire nether dimension folder, it regenerates with no spawners or chests.

After some more testing, I discovered that the problem will go away after deleting world/data/Fortress.dat. So I guess that solves the problem for me, but someone may still need to know where it originated.

Walter van den Berg 2015-10-24T12:24:32Z

This now happened to my hybrid world for 1.9 snapshots. I tried deleting the chunks in MCEdit, but they regenerate without blaze spawners (and presumably chests then, if I read this bug)

On creative I loaded the nether in an earlier version. Upon deleting the chunks in MCEdit, it loads without blaze spawners as well. I can confirm an absence of chests. I will load this ina n earlier version, THEN upgrade, and see if the loot tables are working remotely as intended.

Additional info: talking about 15w43c

seed: -6173601751937638730

Walter van den Berg 2015-10-24T12:59:49Z

Created a new world, went to the nether, found a nether fortress (still 15w43c, mind you), and it had blaze spawners. Can't reproduce.

Walter van den Berg 2015-10-24T13:54:38Z

This bug currently affects1 (out of 2 total) nether fortress, so it doesn't affect them all.

Warren Liddell 2015-11-20T08:34:26Z

I made a custom SMP Map using 15w46a and 8 Fortesses i visited had Loot Chests and Blaze Spawners .. So my assumption is based on maps built//made prior to around 15w38 or so will break Nether Fortress Generation of things.

Raoul Steffen 2016-05-31T19:18:39Z

I encountered the bug in 1.9.4, where it is still present. I can give a better reproduction and a fix that should help find the cause. By my conclusion, it has nothing to do with updating versions and is entirely based on "corrupting" data by deleting parts of it.

Please someone try my reproduction and reopen the ticket if successful.

Reproduction:
1. Start Minecraft 1.9.4.
2. Create a new world, creative mode, Seed -1016733063.
3. Build a Nether Portal, go to the Nether.
4. Teleport to X194 Y73 Z72 and look around so you can see the spawner.
5. Exit Minecraft.
6. From the world folder, delete the "DIM-1" and "DIM1" folder (I know one is for the End, but I don't know which).
7. Restart Minecraft, log into the world.
8. Notice the world regenerates, but the spawner is missing.

Fix:
9. Exit Minecraft.
10. Delete the "DIM-1" and "DIM1" folders again.
11. Delete from the "data" folder the file "Fortress.dat".
12. Restart Minecraft, log into the world.
13. Notice the world regenerates, including the spawner.

Conclusion:
The spawner is generated when the (part of the) fortress first is first added to the "Fortress.dat" file. I expect this will also affect Mineshafts.

Further indication:
I deleted the chunks contining a natural Village with MCEdit. Afterwards, the Village's buildings where regenerated, but there were no villagers. I expect they are also spawned when the Village is first added to the "vilages.dat" file. This may also affect Ocean Monuments and End Cities.

[Mod] redstonehelper 2016-06-01T15:39:58Z

Is there any way to reproduce this without messing with the world save?

Raoul Steffen 2016-06-01T16:02:37Z

I did not find a way to reproduce this without messing with the world save. That is why I called it '"corrupting" data by deleting parts of it'.
For that reason, I would consider this a minor issue. Nevertheless, if a developer has time to spare, they might be able to make the game more robust against such inconsistencies (that are, data in the "Fortress.dat" file for world in not yet generated or deleted chunks). At least at my team we like to keep these things around for these times.

user-f3ac2 2016-07-02T20:22:09Z

Confirming this on 1.10.x.

[Mod] Neko 2016-09-27T23:06:10Z

Most likely invalid due to messing with the world save. @unknown from MC-107367, @unknown from here, and @unknown from here all messed with the world save in some way.

wobst.michael 2017-10-08T15:17:56Z

Cannot reproduce. Please provide proper reproduction steps that don't require messing with the world files.