[MC-8132] Invisible, indestructable block created by piston

I was building a piston-based mob farm (in the Nether), and I found that three of the blocks that I had in front of sticky pistons had disappeared. When I investigated more closely, they were still there, only they were invisible and indestructible by any normal means. I think these are block 36, and when I right-click them, they disappear.

I've seen other bugs talking about this (MC-2167), but I think they are talking about blocks in an active circuit. These blocks remain even if the circuit is disabled.

I do not have a recipe for reproducing this.

This is with a mostly vanilla Minecraft, I'm not running any "mods" and the ONLY thing I've changed is the LWJGL library (to v2.9.0 to avoid sticky key problems). I'll try to make a copy of my world downloadable, but it's more than 10M, so I can't just make it a normal attachment.

Related issues

is duplicated by

MC-9510 Pistons sometimes disappear and lose their function, however their hitboxes are still visible and breakable

MC-17145 Piston bug creates unbreakable block

MC-44154 invisible blocks in survival

relates to

MC-5774 Blocks being constantly pushed by pistons turn invisible after some time

Attachments

laggtest.rar

Comments

migrated 2013-01-22T22:15:07Z

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Ezekiel 2013-01-22T22:26:31Z

You can link to, say, a dropbox download link if you wish to upload the world.

migrated 2013-01-22T22:44:06Z

Here's a copy of the Nether portion of my world. I only included the Nether portion to reduce the size of the download. Add this to any existing world, go to the Nether and go to the coordinates on the screenshot and you'll see the invisible blocks.

http://www.filedropper.com/restore_1

migrated 2013-02-09T21:45:46Z

FYI, the link doesn't work. Is there another way that you can find out what the invisible block is?

migrated 2013-02-10T19:58:30Z

Argh, apparently file-dropper.com deleted the file. It is only supposed to delete it if it has not been downloaded in 30 days, and it's been less than that.

Anyway, so I don't have a backup of that world, and I already destroyed the blocks by right-clicking them.

migrated 2013-03-04T16:27:43Z

Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

migrated 2013-03-04T18:05:42Z

I have not been able to reproduce this, possibly because I don't have a good recipe to reproduce. I'm not convinced that it's actually fixed, but at the same time, I have no evidence that it still exists in a recent snapshot. It should probably be closed, but I don't understand how to change the status myself (if that's even possible).

migrated 2013-03-04T18:06:41Z

Resolving for now.

migrated 2014-07-01T23:43:43Z

I can confirm this both in 1.7.8 and in 1.7.10.
It have happend more than once for me.

The spot where the piston was supposed to be is empty, all you can see is the outline of a block that is a bit of from the position where the piston were before. You can not destroy this invisible block with any tool.

Right now I have 4 holes like this that I just noticed in my whitch farm. The previous ones I mannaged to solve to get back somehow (dont remember how). The original pistons (that are now gone) were moving fast back and forth fast when triggered.

This is observed in multiplayer.
Worth noting is that the server is a bit stressed from time to time giving some lagg when people goes through portals and so on. At those points the server gets the message "Can't keep up .... Running x ms behind, skipping y tick(s).

I have also observed pistons get stuck while both beeing pushed out and retracted at the same time when using a piston/hopper clock. (Dont know if its related) Those pistons are possible to destroy and place again to fix it. (The invissible ones aren't)

migrated 2014-07-02T08:34:41Z

I added a screenshot of it.
As you can see the piston have become invisible.
It can not be broken.
In this screenshot all the 3 holes that you can see are supposed to be pistons (Including the one that I am standing in)

migrated 2014-07-13T14:54:55Z

I found a way to reproduce this while working on solving another bug ( https://bugs.mojang.com/browse/MC-12799 )
They seem to be connected somehow. Anyway.. Ill post a copy of the post I wrote there with the replication method here aswell.

Copy of post with replication from https://bugs.mojang.com/browse/MC-12799 :

Replicated again.
I have now added screenshots and also a world to replicate the problem.

Screenshot information:

"setup" shows the setup that I used.
"invissible_piston" shows one of the invissible block created by a pistonhead after the first time I tried it. Not marked but still there are all the other piston heads, and also invissible blocks instead of the stoneblocks seen in the "setup" picture. Note that the invissible blocks left by the stones are in front of the marked invissible pistonhead of the one marked pistonhead. (to the down left in the picture) So it seems to end in an extended stage.
"faulty_pistonheads" shows what happend after another try I did with the same setup. I think the picture talks for itself.

laggtest.rar is the world download to replicate this yourself.

When entering there should be a sign telling you to teleport to 1000 1000. Do that. and read all the signs to replicate.

Edit: Used 1.7.10 to do this test.