These will be implemented in a future update, as the release was pushed ahead due to the old 'stable' release being completely outdated and no features being offered by it. Old worlds won't be converted automatically, and you can find it lacking some features. You can find them on the release list here on GitHub. Lots of changes have happened since 1.3.12, and they won't be detailed here. This is the first stable build of PocketMine-MP 1.4.

No conversion for old levels (will be added later).

Please do not report lacking features to the bug tracker, only report bugs on implemented features.

Fixed falling sand breaking on full BB partial blocks, closes #2770.

Fixed constructors, default memory to -1, default async generator.

Fix some Chunk corruption due to Chunk overlap.

Fixed players getting kicked for flying when going through special blocks.

TallGrass blocks should be only placed on grass blocks.

Falling sand will become block when in contact with a Liquid.

Return on Level->getSafeSpawn() in case of invalid position.

Fixed #2541 server not saving chunks on chunk unloading.

Added rotation transformations to remaining packet.

Allow placing Snow Layers on top of solid transparent blocks.

Changed max speed per tick from 100 to 10 blocks.

Added GarbageCollectionTask, workaround for weird PHP behaviour when using -disable-ansi.

Fixed Flat generator on existing chunks, region issues.

Fixed Entities being placed in recreated chunks.

Catch more corruption issues in Region-based worlds, fixed first chunk being generated on an invalid sector.

Improved chunk saving times by not marking it as changed when Players are added/removed.

Fixed visual typo in /ban-ip, closes #2503.

Fixed #2489 Falling Sand drops as an item when not expected.

Fixed #2488 Player suffocates when putting blocks to climb higher.

Changed generator choosing logic, add proper preset if needed, fixes #2751.

Implemented double chest fix, closes #2744, fixes #2493.

Implemented hardcore banning, closes #2574.

Implemented proportional armor modifier, applied armor in other damage types and consume armor when player is damaged.

Improved threading and resource usage, new defaults.

Allow plugins to cancel some kicks better, closes #2743.

Implemented Threaded ClassLoader, improves class loading while on different threads (no need to synchronize states).

Added Entity->fastMove() for players and direct-controlled entities.

Fixed issue where plugins schedule a Player update before log in.

Added Level->getChunks(), fixed some Doc Comments.

Ignore spawn protection when no ops are set.

Automatic resource freeing on Region-based worlds.

Fixed some strange crashes on broken systems.

Improved chunk saving and reduced world corruption.

This version has API changes, bumping the version to 1.11.0, and it won't be bumped again until a stable build is released.

Minecraft pe 12.3 update