Hostile Mobs don't Spawning

Hostile mobs don't spawning.

SOLVED

I am using spigot 1.14.4

Diffuculty is hard

(Mobs can spawn in spawners)

monster is on in the settings.

plugins are :

ChangeSkin

ChangeSkin.jar

CrisTreeCapitator

CrisTreeCapitator.jar

PluginMetrics

ProtocolLib

ProtocolLib.jar

SpawnerSilk

SpawnerSilk-2.1.jar

Updater

bStats

Quote from Mc88Donalds

use 1.14.2

But this can break the world .I don't want to delete the world and start over the survival again.

thank you