Put in console during startup of Spigot 1.8.8 once:

[14:06:37 WARN]: java.lang.reflect.InvocationTargetException
[14:06:37 WARN]: 	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
[14:06:37 WARN]: 	at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
[14:06:37 WARN]: 	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
[14:06:37 WARN]: 	at java.lang.reflect.Constructor.newInstance(Unknown Source)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.base.loader.Loader.<init>(Loader.java:20)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.base.loader.SpigotLoader.onEnable(SpigotLoader.java:12)
[14:06:37 WARN]: 	at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:321)
[14:06:37 WARN]: 	at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:340)
[14:06:37 WARN]: 	at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:405)
[14:06:37 WARN]: 	at org.bukkit.craftbukkit.v1_8_R3.CraftServer.loadPlugin(CraftServer.java:357)
[14:06:37 WARN]: 	at org.bukkit.craftbukkit.v1_8_R3.CraftServer.enablePlugins(CraftServer.java:317)
[14:06:37 WARN]: 	at net.minecraft.server.v1_8_R3.MinecraftServer.s(MinecraftServer.java:414)
[14:06:37 WARN]: 	at net.minecraft.server.v1_8_R3.MinecraftServer.k(MinecraftServer.java:378)
[14:06:37 WARN]: 	at net.minecraft.server.v1_8_R3.MinecraftServer.a(MinecraftServer.java:333)
[14:06:37 WARN]: 	at net.minecraft.server.v1_8_R3.DedicatedServer.init(DedicatedServer.java:263)
[14:06:37 WARN]: 	at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:525)
[14:06:37 WARN]: 	at java.lang.Thread.run(Unknown Source)
[14:06:37 WARN]: Caused by: me.TechsCode.UltraCustomizer.gson.JsonSyntaxException: java.io.EOFException: End of input at line 1 column 12 path $[1]
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.gson.internal.Streams.parse(Streams.java:58)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.gson.JsonParser.parse(JsonParser.java:84)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.gson.JsonParser.parse(JsonParser.java:59)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.gson.JsonParser.parse(JsonParser.java:45)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.tpl.storage.dynamic.implementations.LocalFile.get(LocalFile.java:83)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.tpl.storage.dynamic.DynamicStorage.<init>(DynamicStorage.java:28)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.FolderStorage.<init>(FolderStorage.java:11)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.UltraCustomizer.onEnable(UltraCustomizer.java:33)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.base.TechPlugin.<init>(TechPlugin.java:39)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.base.SpigotTechPlugin.<init>(SpigotTechPlugin.java:19)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.UltraCustomizer.<init>(UltraCustomizer.java:22)
[14:06:37 WARN]: 	... 17 more
[14:06:37 WARN]: Caused by: java.io.EOFException: End of input at line 1 column 12 path $[1]
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.gson.stream.JsonReader.nextNonWhitespace(JsonReader.java:1401)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.gson.stream.JsonReader.doPeek(JsonReader.java:467)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.gson.stream.JsonReader.hasNext(JsonReader.java:414)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.gson.internal.bind.TypeAdapters$29.read(TypeAdapters.java:714)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.gson.internal.bind.TypeAdapters$29.read(TypeAdapters.java:698)
[14:06:37 WARN]: 	at me.TechsCode.UltraCustomizer.gson.internal.Streams.parse(Streams.java:48)
[14:06:37 WARN]: 	... 27 more

Spammed in console after server is started:

[14:05:17 ERROR]: Could not pass event UpdateEvent to UltraCustomizer v1.1.2
org.bukkit.event.EventException
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[spigot.jar:git-Spigot-21fe707-e1ebe52]
	at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[spigot.jar:git-Spigot-21fe707-e1ebe52]
	at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [spigot.jar:git-Spigot-21fe707-e1ebe52]
	at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [spigot.jar:git-Spigot-21fe707-e1ebe52]
	at me.TechsCode.UltraCustomizer.tpl.task.TaskManager$1.run(TaskManager.java:14) [UltraCustomizer.jar:?]
	at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftTask.run(CraftTask.java:71) [spigot.jar:git-Spigot-21fe707-e1ebe52]
	at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:350) [spigot.jar:git-Spigot-21fe707-e1ebe52]
	at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:723) [spigot.jar:git-Spigot-21fe707-e1ebe52]
	at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:374) [spigot.jar:git-Spigot-21fe707-e1ebe52]
	at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:654) [spigot.jar:git-Spigot-21fe707-e1ebe52]
	at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:557) [spigot.jar:git-Spigot-21fe707-e1ebe52]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_201]
Caused by: java.lang.NullPointerException
	at me.TechsCode.UltraCustomizer.UltraCustomizer.getFolders(UltraCustomizer.java:56) ~[?:?]
	at me.TechsCode.UltraCustomizer.scriptSystem.objects.Constructor.call(Constructor.java:53) ~[?:?]
	at me.TechsCode.UltraCustomizer.scriptSystem.objects.Constructor.call(Constructor.java:83) ~[?:?]
	at me.TechsCode.UltraCustomizer.scriptSystem.elements.constructors.Repeating.tick(Repeating.java:58) ~[?:?]
	at sun.reflect.GeneratedMethodAccessor21.invoke(Unknown Source) ~[?:?]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_201]
	at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_201]
	at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[spigot.jar:git-Spigot-21fe707-e1ebe52]
	... 11 more