Failed to start the minecraft server
java.lang.NullPointerException
        at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:213) ~[factions.jar:git-PaperSpigot-"4c7641d"]
        at com.google.common.collect.Lists$ReverseList.<init>(Lists.java:767) ~[factions.jar:git-PaperSpigot-"4c7641d"]
        at com.google.common.collect.Lists.reverse(Lists.java:759) ~[factions.jar:git-PaperSpigot-"4c7641d"]
        at net.minecraft.server.v1_8_R3.UserCache.b(UserCache.java:191) ~[factions.jar:git-PaperSpigot-"4c7641d"]
        at net.minecraft.server.v1_8_R3.UserCache.<init>(UserCache.java:70) ~[factions.jar:git-PaperSpigot-"4c7641d"]
        at net.minecraft.server.v1_8_R3.MinecraftServer.<init>(MinecraftServer.java:126) ~[factions.jar:git-PaperSpigot-"4c7641d"]
        at net.minecraft.server.v1_8_R3.DedicatedServer.<init>(DedicatedServer.java:43) ~[factions.jar:git-PaperSpigot-"4c7641d"]
        at net.minecraft.server.v1_8_R3.MinecraftServer.main(MinecraftServer.java:984) [factions.jar:git-PaperSpigot-"4c7641d"]
        at org.bukkit.craftbukkit.Main.main(Main.java:201) [factions.jar:git-PaperSpigot-"4c7641d"]
root@HereCraft:~/factions#