Relogging can cause observers to emit pulses

Hi Tal,

How have you tested this in 1.15? Changes were made to observers from my understanding so its possible this behaves differently now, are you able to upload footage of your test?

Ionic

@unknown

I tested it as I said... in the game, you can see the video right now in the attachments.

And the only one thing that changed in 1.15 to observers is the fact that observers won't detect a change when gets placed, here is the changelog if you want:

https://feedback.minecraft.net/hc/en-us/articles/360040027711-Minecraft-Beta-1-15-0-53-Xbox-One-Windows-10-Android-

In any case, it's not in any way related to this problem.

From now on I will always have to do this? It's pretty frustrating

It helps us to confirm that it has actually been tested (and isn't just someone bumping a thread they want fixed) so we can update the affected versions.

I also got a little confused by it saying "Tested before reported", wasn't sure if that meant it was tested prior to being reported on the tracker. All good, have updated the affected versions for you.

I have a theory as to why observers detect powered redstone dust upon relog.

It might be because the game doesn't save anything redstone related and has to recalculate which blocks are powered and things like that, meaning the dust actually changes state, which the observer then detects. This could probably be fixed by just saving that information when you leave the game.

It should also be noted that this does not occur when chunks are unloaded and reloaded, nor when you leave and rejoin someone else's world. This is part of the reason why I think the saving process is to blame.

Observers also fire on relog when facing double chests. Doesn't happen with single chests

Just found this ticket for this issue. I originally reported this as MCPE-25840 long ago but it got closed for inactivity.

Affects 1.16.100.53

Affects 1.16.100.55 Beta.

Affects 1.16.100.56 beta.

Affects 1.16.100.58 Beta.

Affects 1.16.210

I found this bug in a multi item sorter that I plan to build. I did some testing and here is a list of blocks that when observed occur thus bug:

Powered redstone

Item frames (with or wothout items)

Container blocks with a minimum of 1 item (with the exeption of hoppers). (When the containwr has no items this bug does not occur)

Double chests (with or without any item)

I tested on the version 1.16.210 on bedrock edition

affects 1.16.220.2, and current betas.

Affects 1.17.0.50

Affects 1.17.11

I have a contraption in which when you light up a campfire, an observer detects it and triggers some dispensers that light up other campfires in the area. The observer is connected to a piston and appearently the relogging pulse is long enough to trigger the piston and make me find the campfires always lit, which is not supposed to be.

Affects 1.17.30

Players are designing reload proof 2-way flying machines using this bug. It would be helpful to know if Mojang plans to fix these or not

This bug continues to affect 1.18.2

I have a sugar cane farm harvested by a two way flying machine, and the hopper minecarts which collect it all are activated and deactivated by a dropper-hopper based flip-flop which is pulsed through a repeater by observers when the machine leaves or arrives at a station. On loading the world, one of the two observers is facing lit redstone, and that observer fires and triggers the flip flop, reversing the activation/deactivation of the minecart unless it is manually reset after loading. 

Affects 1.18.10 with Barrels. On Nintendo Switch.

I hope Mojang fixes this because reload proofing forces me to redesign my stuff

Affects 1.19.20

It could be useful to have a couple of specific objects do this as a part of game mechanic (by design) way of detecting loading. But most of the current list could make redstone designs unnecessarily more complicated.

1.19.31

1.19.51 as well

1.20.15 as well

Issue present in 1.21

This is breaking a number of shulker loader designs which are in high demand with the new Crafter block.  Hopefully this gets fixed urgently as it makes the Crafter less useful

The addition of copper bulbs has really exacerbated this issue. I've made a few designs now with observers toggling copper bulbs, and they work fine when the world stays loaded but (sometimes, unpredictably, in some chunks but not others) lose their minds on save/restore since the bulb state gets toggled when nothing happened. At first I thought it was an issue with save/restore of copper bulbs themselves, but I eventually traced it to this long-standing observer bug.

Attached world ("MCPE-29548") with a copper bulb repro case. Observer watches redstone dust (toggled by lever) and powers bulb. The mechanism does not cross a chunk border.

Expected behavior: redstone dust and observer bulb stay in sync (both active or neither active) including across world save/load.

Observed behavior: powering dust then relogging results in out-of-sync state (dust powered, bulb off).