When pressing right click once, it's actually presses twice for some reason.

Most likely your mouse; I used to have this issue too; it is very unlikely that the game would do this, try with a different mouse.

I have tried three different mice. I am fairly sure it is the game and I believe it happens when you are placing blocks on tick update.

It makes little sense to me how tick updates will have anything to do with the placing command. But even if this is the case, I have never had this issue with a mouse that works fine (like it does now). Maybe it's something else. Dunno, it's just my opinion.

I have Windows 7 64 bit, an Intel Corei7 processor 2.00GHz, 6GB RAM, and an NVIDIA GeForce GT 520M. If anyone can tell me what in that list may cause the issue, I will send cookies. I think this may also be related to the issue where items lag back into storage boxes from my inventory... (both issues are really driving me nuts. I do not like having to go back over an area to clean up the double stack of blocks or go back to the storage box five times because I went to grab something and it suddently wasn't there).

I didn't mean to say that it is a hardware problem. As for the storage bug, that I haven't seen ever nor heard of it before.

Sorry, I meant that if it is, it would explain why it seems only a few people seem to suffer from it. It's very much a double-placement of blocks. I'm not running or holding down anything, just slowly trying to place one block at a time and in one swoop two or three blocks might appear. If I get some time this week I'll try and make a video. As for my inventory rubber-banding, thanks! I will check to see if there's another ticket and then post if there isn't. I didn't realize these issues weren't widespread!

This bug happens consistently on one of my computers and I'd be glad to help a developer try to reproduce it. What information would be useful for me to provide? A screencast, or some kind of debug output?

Andrew, you might force a crash by pressing F3 + C for 10 seconds while ingame and attach the crash report here.

That happens to me as well, and I have a similar clock speed to Kelsey at 2.1GHz. It seems to happen the more manual blocks that are in the game and its very annoying

I dont think faulty mice are the problem, in my opinion, its the lag produced when placing/removing a block as I have experienced lag while doing it and during that lag, 2 or more blocks have been placed/removed. And this becomes more apparent the more blocks that are placed in the game

I suggest this is a result of not capping the frame time in your simulation. This appears to happen very regularly on low-end machines, and is often described as being associated with frame rate spikes. (Probably a result of a garbage collection.) With an uncapped frame time, the wall clock time delta is larger than the block placement threshold, even though the simulation was non-interactive during the delta.

This should be fixable by either capping the frame time, or resetting the block placement time when a large frame time is detected.

Kevin, for those of us not as familiar with debugging, can you please tell me how to do that so I can test if it works please? You can email me at [email protected] as well.

This is more of a development issue than a debugging issue. The changes I mentioned can only be made from source code.

I have uploaded the requested crash report. I went to a world which I have had extensive problems with this bug on (and yes, some worlds are worse than others) and was able to trigger this bug within less than a minute of loading the world. The bug is easiest to reproduce when the game is lagging some other way already (like it was when I forced this crash, since it was still loading nearby chunks), but the problem occurs even when the game is not lagging (just less frequently).

I have also attached another crash report where I set my render distance to short and waited for everything to load (Chunk Updates: 0). I triggered the bug without issue simply by placing blocks. It now happens on that particular world every time I place a block inside one particular tower of my castle. I'll attach the world data if someone will tell me which particular files I'll need to upload (I normally just copy the whole folder for a given world, but you can only upload individual files here, and it's way too big anyways).

It is, by the way, still an issue in 1.5.1

I tested this above ground in a forest with a lot of lights. It would place 2 blocks instead of 1 every time. Then I went underground into a small room with no lighting. It always placed a single block. Also, in a superflat world with nothing in it, it will always place a single block.

@ Garrett Cotta " Also, in a superflat world with nothing in it, it will always place a single block." eeehhhh, yes it does. I just started a new superflat and was reproducing it about 20 seconds.

What Garrett Cotta says about the lighting might just be onto something. The castle tower which has been giving me so much grief has alternating top-half and bottom-half slabs as ceilings/floors, and stairs used to make arrow-slit-like windows with corner stairs used so that the wall is only half-thickness. It could be possible that that is screwing around with the lighting engine and causing the game to lag each time it lights the world. Perhaps something to do with the transparency/lack-thereof of slabs?

This sounds like it might be valid especially because it is only within the confines of the tower that the problem is ridiculously evident. Elsewhere, it only happens from time to time, though sometimes it will "follow" me around even after I leave the tower, forcing me to restart the client to clear it (which doesn't even always work).

I can indeed confirm that it is light-related. I have two test worlds that are identical, except for what I have built at spawn. one has a large piston elevator which is fully lit in the wiring, and the other has an identical elevator without the torches. this means that there is a lot which will update light, even if it does not end up changing the level(I don't know if this is intended). so If I adjust a repeater in the affected region, even though it does not change the light level, it updates all the light around it, and that causes a chain reaction with all the other blocks that experience this behaviour. also it DOES happen on an unmodded client, but I am using optifine to disable all unnessecary things, to minimise graphics process load, I have render distance on tiny, and my computer's power option set to high performance, and it still happens.

edit: after a recent computer update, I am not getting the double-click effect, however I am still getting the lag spike.

I have this problem constantly on both of the computers I have Minecraft installed on. When building I will almost always place two blocks instead of one. This is especially annoying when the block is something like a slab as the game has a nasty habit of breaking both the copy and the block I placed. On occasion the game will place three blocks at once. I think there should be an option to make it so that you have to remove your finger from the button before it allows you to place another block.

Can we get some feedback from the mods on whether this has been/is being addressed, and when we might see a fix for it?

We don't know.

It's not so bad with regular blocks, but with smooth stone it is a pest and with obsidian it's pretty awful if you don't have an diamond pickaxe enchanted with speed.

I appear to have fixed it on my computer, i bought a new graphics card an AMD radeon 4000 series and before i couldn't even try to place one block without the game placing two or three, but since i got the graphics card up an running i haven't seen it since and the fps have increased drastically, i was previously using the built in graphics card and from what I've seen so far it has absolutely nothing to do with the ram in the computer or mouse but just the graphics card.

Your Radeon may be able to handle it, but a lot of people who really enjoy Minecraft aren't big gamers otherwise, so they don't have that sort of hardware. I, for one, am running Intel integrated graphics, at least for now. Even with a three-year-old processor's integrated graphics, Minecraft runs fine except for this...it's not a graphics-heavy game, so this kind of slowdown seems to indicate an oversight of some sort that's causing the game to be affected way more than it should.

Also, see what people like James Hall have said (above). Skyrim should be harder on the hardware than Minecraft.

I'd also like to chip in and say that I can play Skyrim easier than I can play Minecraft (not on full settings though, jealous). There are some worlds where this seems worse than others for me. Strangely enough, a LAN game that my household plays is (almost) fine, only a few complaints and they are infrequent. However on a super-flat creative mode this happens every time, resulting in at least two blocks being placed when I try to place one. This has become unbearable while experimenting with redstone due to me having to spend at least three times as long placing each section (redstone itself is fine; you cannot put 2 on top of each other). I have tried tapping the mouse as lightly as possible to no avail; the game freezes for half a sec and two or three blocks are placed.
My laptop has an integrated intel graphics card, java is updated to the most recent, as is Minecraft and my graphic card's drivers.

Don't have a lot of trouble playing minecraft, but sometimes I really click once, and without lagg it just places 2 blocks (about 1 game tick apart I think, it's really fast, even faster than the max building speed on creative....yes). Rarely it even places 3 blocks. I have played creative mode for a while prior to this (and some survival) and never had this issue. I think I started playing in 1.5.2 if that helps.

Edit: this also happens with levers sometimes.

Edit2: it's my mouse (razer naga).

Can anyone experiencing this issue try the new launcher https://mojang.com/2013/06/minecraft-snapshot-13w25a/ with 1.5.2 or even the current snapshot ?

This never happened to me till 1.6.1 and it's really annoying! When will they fix it!!????

From all the testing that I have done I am sure that it is a lighting error and that it can only be prevented by improving the memory(ram) or graphics hardware of the computer. I know this because I done both these things and the error hasn't happened since, it doesn't seem to be anything to do with the programming of minecraft just the current capabilities of the computer that minecraft is being played on.

I have also found that the error isn't effected by the mouse or by the computers OS as mine is windows xp and minecraft runs fine now that I have replaced some of my computers hardware.
(Edit)
After further testing I have found out that the ram does not play a part in this error, my computer only has 1GB and I have seen that people with 8GB of ram having the error.

Whoever is in charge of this one it would be greatly appreciated if there's some way to add something in options where you have to click each time you want to place a block like I believe it used to, rather than holding the button down, as I believe this would make the game playable again for people having this issue like myself.

Windows 7 64-bit
Dual core 2.13GHz processor
8GB Ram

1.6.2 seems to have (sort of) done it for me. Now right click takes mutliple hits to do anything (which could be mouse, it's getting kind of old now), so I just swapped the command to my R key. Now 1 click = 1 block again. I'll keep watching for it, but if this fixed something, thank goodness!

I was so excited when I read your response, but I tried it and no help, still double-places/breaks blocks, it's always done this to me since they made it where you could just hold the button down to place blocks a long time ago. As someone else pointed out, I think it may happen more when there are empty spaces below you like a multi-story house.

Easy way to test your mouse if it's the faulty one: http://unixpapa.com/js/testmouse.html

It cant be the mouse. I have tried to use the keyboard to "rightclick" and the same thing happens. Could it be the game aint compt with Win7?

Nope, not Windows 7, otherwise I'd still have it... right? o.0

Either way, I can no longer replicate this bug in any of my games. This is really weird. The only thing I really changed recently is that we moved and have a different ISP since 1.6.2 came out. Anyone try this online vs offline? Also, anyone else running off a laptop? I've always kind of wondered since I play on a laptop and my boyfriend a normal desktop, and he's never had it... :S

Im going to try the game on my "old" XP stationary and se if that helps. I'll post later if it helps

It works like a charm on my old stationary. I think it could be that the game has problems with laptop grafic cards, or maby just intel's cards. I worked with game support earlyer and notised that many games had problems with buildtin grafic cards, espeialy Intel's cards.