If I start it normally when the server is starting it crashes without any errors.
If I try to enable it manually with a plugin it appears:
java.lang.NullPointerException: null
at com.yapzhenyie.GadgetsMenu.cosmetics.pets.TypeManager.register(TypeManager.java:96) ~[?:?]
at com.yapzhenyie.GadgetsMenu.cosmetics.pets.TypeManager.initializePets(TypeManager.java:18) ~[?:?]
at com.yapzhenyie.GadgetsMenu.GadgetsMenu.onEnable(GadgetsMenu.java:257) ~[?:?]
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:264) ~[server.jar:git-Spigot-dcd1643-e60fc34]
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:337) [server.jar:git-Spigot-dcd1643-e60fc34]
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:403) [server.jar:git-Spigot-dcd1643-e60fc34]
at com.rylinaux.plugman.util.PluginUtil.enable(PluginUtil.java:62) [PlugMan.jar:?]
at com.rylinaux.plugman.command.EnableCommand.execute(EnableCommand.java:127) [PlugMan.jar:?]
at com.rylinaux.plugman.PlugManCommandHandler.onCommand(PlugManCommandHandler.java:95) [PlugMan.jar:?]
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) [server.jar:git-Spigot-dcd1643-e60fc34]
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:141) [server.jar:git-Spigot-dcd1643-e60fc34]
at org.bukkit.craftbukkit.v1_12_R1.CraftServer.dispatchCommand(CraftServer.java:648) [server.jar:git-Spigot-dcd1643-e60fc34]
at net.minecraft.server.v1_12_R1.PlayerConnection.handleCommand(PlayerConnection.java:1399) [server.jar:git-Spigot-dcd1643-e60fc34]
at net.minecraft.server.v1_12_R1.PlayerConnection.a(PlayerConnection.java:1234) [server.jar:git-Spigot-dcd1643-e60fc34]
at net.minecraft.server.v1_12_R1.PacketPlayInChat.a(PacketPlayInChat.java:45) [server.jar:git-Spigot-dcd1643-e60fc34]
at net.minecraft.server.v1_12_R1.PacketPlayInChat.a(PacketPlayInChat.java:1) [server.jar:git-Spigot-dcd1643-e60fc34]
at net.minecraft.server.v1_12_R1.PlayerConnectionUtils$1.run(SourceFile:13) [server.jar:git-Spigot-dcd1643-e60fc34]
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_261]
at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_261]
at net.minecraft.server.v1_12_R1.SystemUtils.a(SourceFile:46) [server.jar:git-Spigot-dcd1643-e60fc34]
at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:748) [server.jar:git-Spigot-dcd1643-e60fc34]
at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:406) [server.jar:git-Spigot-dcd1643-e60fc34]
at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:679) [server.jar:git-Spigot-dcd1643-e60fc34]
at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:577) [server.jar:git-Spigot-dcd1643-e60fc34]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_261]