Mark McKenzie

Minecraft is broken for all iPhone and iPad devices. It works on Xbox and windows 10. 

The workarounds don’t work. The problem is seems to be with hotfix v1.14.1. It causes the app to lock up at various points shortly after starting the app. Breaks all iPhone and iPad play. This a paid app and it seems like it’s broken for everybody.

I have the exact same issue as Martin on an iPad and two different iPhones. The problem started today — it worked on everything last time we tried, last weekend.

Added screenshots of the test setup showing one of multiple locations where tripwire is failing to trigger (another spot 16 layers upward can be seen in the distance).

I uploaded a Minecraft 1.8.3 world (Ghast Tripwire Sieve.zip) with a self-replicating setup to test multiple combinations of ghast and tripwire elevation.

This appears to be a modular arithmetic issue, presumably in how the game checks if tripwire in one section is triggered by an entity in the lower section. A ghast at any height h (integer or floating point) with (h mod 16) > 14.0625 will fail to trigger tripwire in the third layer of the next section up, and if (h mod 16) > 15.0625, tripwire in the fourth layer should also trigger but fails to (eg. a ghast summoned at Y=15.5 will trigger tripwire in layers 16 and 17 but fails to trigger tripwire in layers 18 and 19).

I may upload a demonstration world tomorrow (no promises).

This issue is only known to happen at one particular combination of ghast height and tripwire height. The title was originally vague because I didn't (and still don't) know if this problem could be reproduced at any other particular combination of heights; I figured a title that was too specific might cause people to overlook that unknown, but apparently they aren't reading the important detail clearly listed in the description.

If you can't reproduce a bug, please don't post that you couldn't reproduce it until you've checked that you didn't miss something important in the description. A vague statement of inability to reproduce will mislead others looking over the problem and make those who have already reproduced the problem have to check it again (possibly leading to a vicious circle); giving details from the reproduction attempt helps to identify the problem but can also cause noise if it neither correctly tests the issue nor identifies another arrangement as also producing the problem ("Problem doesn't occur at <conditions not claimed to cause problem>" vs "Problem also found with <different conditions>").

It's reasonable for reviewers to not want to immediately download an untrusted file but I will add a demonstration world from 1.8.3, and a new screenshot showing the altitude in the debug overlay (in addition to the ghasts on each side already showing that the problem does not occur at every height).

This problem also occurs in Minecraft 1.3.1 (the first release featuring tripwire) but the Affected Versions field doesn't support adding a version that old.

Same results with a matching world created from scratch in 14w31a (launcher 1.5.1, java 7 update 65) - the ghast trapped at ground level will not trigger the tripwire, but the whole setup one layer higher or lower works fine.

I did not re-test the attached world, and I don't remember where the engineering world where I first found the bug is, so I can't check that one.

The preset screen in 14w31a kept resetting the old custom preset after entering it, clicking Use Preset and then Done; the preset 3;207*minecraft:stone;1;1 works and I have updated the instructions above.