This works as intended.
Acc. to the Minecraft Wiki bone meal has no effect on kelp.
In the engish version of the wiki is no entry for this behavior but on the german page you find some information about this.
Can't confirm, my world loads as expected without any issues updating from pre8 to pre9.
A crash report or information about PC specifications might be helpfull for the Helper/Mods here.
In which gamemode were the endermites created?
Enderman only react to Endermites randomly spawned through throwing enderpearls in Survival-Mode.
I have two working Enderman farms in several 1.12.2 worlds without any issues.
Might the trapdoor issue relate to the following issue?
MC-132358
Maybe you can rebuild the farm with the oak-wood trapdoors and check the behavior of the creeper again.
Can confirm for 1.13pre6.
Was standing on a small island during nighttime in an ocean biome surrounded by drowneds and they didn't left the water.
Can't confirm. I've already found three treasure maps in 1.13pre6.
Same here. Everytime I click on a recipe without having all the ingredients the game is crashing.
Local single player the client is crashing
While playing on server the client is crashing, but server is still running without effect
Affected Version: 1.13 pre.release
After hours of breeding I got every type of Villager, but the spawning rate for
Librarian and Cartographer is very low - approx. 24:1 (where 24 represents all other types).
Same problem here.
It's affecting our new installed SMP-Server for version 1.13 and currently updated to 1.13.1.
We are playing on hard mode.
Except from Enderman only Phantoms are spawning like intended and some Zombie Pigmans, but sitll very low compared to 1.12. For all other mobs the spawn rate is nearly zero.
None of my mob farms are working (only Enderman farm is working fine). At night there are no mobs spawning or at least just a handfull in total within 1-3 hours. Even in unexplored caves nearly no mobs are spawning.
A few days ago our serveradmin reinstalled the minecraft server-software. For a few hours the spawning rate was very fine and all farms were working but then the spawning rate dropped again to nearly zero...
To be honest, the only danger at night are the phantoms... if you don't sleep...
Hope this will be fixed soon.
UPDATE
As in Issue MC-134506 described, mobs only spawn when moving around. I've tested this case with my AFK mob farm (design by gnemban). While standing AFK, no mobs were spawning. After flying around the farm with Elytra the spawning rate increased temporarily, until I went AFK again.