Help Server Crashing

[iiEnderr]

Hello my server is constantly crashing and I've been trying to diagnose the problem for an hour now and haven't found a solution.
Logs:
[06:38:49] [main/FATAL]: Failed to start the minecraft server
java.lang.NullPointerException
at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:213) ~[paperspigot-1.8.jar:git-PaperSpigot-a5bb700-f27339c]
at com.google.common.collect.Lists$ReverseList.<init>(Lists.java:767) ~[paperspigot-1.8.jar:git-PaperSpigot-a5bb700-f27339c]
at com.google.common.collect.Lists.reverse(Lists.java:759) ~[paperspigot-1.8.jar:git-PaperSpigot-a5bb700-f27339c]
at net.minecraft.server.v1_8_R3.UserCache.b(UserCache.java:191) ~[paperspigot-1.8.jar:git-PaperSpigot-a5bb700-f27339c]
at net.minecraft.server.v1_8_R3.UserCache.<init>(UserCache.java:70) ~[paperspigot-1.8.jar:git-PaperSpigot-a5bb700-f27339c]
at net.minecraft.server.v1_8_R3.MinecraftServer.<init>(MinecraftServer.java:130) ~[paperspigot-1.8.jar:git-PaperSpigot-a5bb700-f27339c]
at net.minecraft.server.v1_8_R3.DedicatedServer.<init>(DedicatedServer.java:43) ~[paperspigot-1.8.jar:git-PaperSpigot-a5bb700-f27339c]
at net.minecraft.server.v1_8_R3.MinecraftServer.main(MinecraftServer.java:979) [paperspigot-1.8.jar:git-PaperSpigot-a5bb700-f27339c]
at org.bukkit.craftbukkit.Main.main(Main.java:201) [paperspigot-1.8.jar:git-PaperSpigot-a5bb700-f27339c]

 

[Ritzzzez]

custom spigot? if so it is the problem.

at org.bukkit.craftbukkit.Main.main(Main.java:201) [paperspigot-1.8.jar:git-PaperSpigot-a5bb700-f27339c]