Unfortunately 1.13.1-v3 was shown still contain several bugs on various versions of MC conditionally, which had to be fixed. Many are very specific to other plugins of ours, so those will be mentioned.

Fixes

• Heightmap calculation was incorrect on MC 1.12.2 and earlier. This caused Light Cleaner to malfunction on older versions of Minecraft.
  
• Changing weather did not work on MC 1.13 and later. This caused My Worlds weather changes to no longer function on >1.13.
• Performance problem with the world listener hook impacting all versions of MC, when a lot of block physics occur. Performance loss here has been greatly minimized.
• Template initialization error on MC 1.9 - MC 1.11. This caused Traincarts to not function on these versions of MC.
• Entity world border field could not be set on MC 1.9.4
• Item frame DATA datawatcher key nonfunctional. May have caused strange item-frame map display glitches on MC 1.9 - 1.10.2.
• Player position is maintained when switching between controlling a map display map or walking around. Also fixes a random bug where a player is partially submerged inside a block when controlling.