Bugged Skulls?

[L4BORG]

[23:12:04 WARN]: java.lang.IllegalArgumentException: Name and ID cannot both be blank
[23:12:04 WARN]:        at com.mojang.authlib.GameProfile.<init>(GameProfile.java:25)
[23:12:04 WARN]:        at net.minecraft.server.v1_10_R1.UserCache.a(UserCache.java:90)
[23:12:04 WARN]:        at net.minecraft.server.v1_10_R1.UserCache.getProfile(UserCache.java:158)
[23:12:04 WARN]:        at net.minecraft.server.v1_10_R1.Village.b(Village.java:444)
[23:12:04 WARN]:        at net.minecraft.server.v1_10_R1.PersistentVillage.b(PersistentVillage.java:256)
[23:12:04 WARN]:        at net.minecraft.server.v1_10_R1.PersistentCollection.a(PersistentCollection.java:99)
[23:12:04 WARN]:        at net.minecraft.server.v1_10_R1.PersistentCollection.a(PersistentCollection.java:84)
[23:12:04 WARN]:        at net.minecraft.server.v1_10_R1.WorldServer.a(WorldServer.java:1083)
[23:12:04 WARN]:        at net.minecraft.server.v1_10_R1.WorldServer.save(WorldServer.java:1024)
[23:12:04 WARN]:        at org.bukkit.craftbukkit.v1_10_R1.CraftWorld.save(CraftWorld.java:823)
[23:12:04 WARN]:        at net.minecraft.server.v1_10_R1.MinecraftServer.C(MinecraftServer.java:755)
[23:12:04 WARN]:        at net.minecraft.server.v1_10_R1.MinecraftServer.run(MinecraftServer.java:629)
[23:12:04 WARN]:        at java.lang.Thread.run(Thread.java:745)

Already tried removing cache file... didn't help.

[grzegorzekkk]

Something is definitely wrong.
A lot of my players get client crashes while having skull in inventory.

[L4BORG]

With https://www.spigotmc.org/resources/skull-exploit-fix.26099/ issue went away for us...