Subhasis Banerjee
Comments
I have confirmed that this is not the issue. They do spawn even when there is a ceiling above the area. However, they spawn very rarely no matter what. Place yourself at a suitable AFK spot between 24 and 32 blocks above the floor and wait. You may wish to use /kill @e to kill off all other entities so that the area does not hit mob cap.
Possible duplicate of MCPE-37325?
I am suffering from the same issue. They spawn only when I fill all blocks above them with air. I will play with the issue a bit and try to create a set of commands to reproduce the issue in real-time.
Edit: I created a superflat and flew over it (I flew higher than Y:35) for quite a bit, but couldn't locate a single slime during the day. They were spawning in night, but as soon as I lit that area up, they disappeared. It seems those are swamp chunks... which I obviously can't tell due to the map being a superflat.
Here is all I could find about this bug:
Description: While climbing a slope, minecart is visually sinking 0.5 block into ground every time it climbs a block whose Y axis value equals 2^n. tested values: Y:15->Y:16; Y:31->Y:32; Y:63->Y:64.
Condition: When I take a minecart down the slope, it does not glitch when returning back up up to its origin point. The glitch happens only if the minecart goes higher than its origin. However, reloading the game resets the minecart state and therefore the cart will glitch during the climb even if you came down using that minecart before reloading the game.
Quick steps to reproduce:
Create a 45° sloped rail line from Y value (height) 20 to 40.
Place a minecart at the bottom of the rail and ride the cart to the top.
Observation:
The cart will sink half a block as soon as it climbs Y:32.
Further observations:
1. Notice that the coordinate on the 1st attached picture displays Y value of 62 even though standing on the minecart there displays y value 64. That cart started below Y:32 and has sunk twice. Even though visually it sinks only half a block every time, the data value shows otherwise.
2. This can happen repeatedly and sink the minecart further into the ground.
3. The sunken minecart sinks further into ground if attempt is made to recvover it from above. It must be recovered by digging under it.
4. After reloading the game, the minecart returns to its normal position above ground.
5. Going downhill does not fix a glitched cart, but going below the point that triggered the glitch raises the glitched cart by one block.
6. This happens on both survival and creative mode.
7. This glitch does not depend on the direction of the rail line. It happens across both North-South and East-West rail lines.
8. If the glitched cart attempst to jump down on rails that are two blocks below its current track, it fails to land on the bottom track and becomes a floating ghost cart in the air.
I am not noticing this bug in 1.8.0.13 anymore. Looks like a solution has been found. Thanks devs.