Since Spigot 1.10, my server crashes 1/2 times when i start it, or some hours later.

[11:33:34] [Server thread/ERROR]: Encountered an unexpected exception
net.minecraft.server.v1_10_R1.ReportedException: Exception ticking world
at net.minecraft.server.v1_10_R1.MinecraftServer.D(MinecraftServer.java:799) ~[spigot-1.10.jar:git-Spigot-6016ac7-10c10b3]
at net.minecraft.server.v1_10_R1.DedicatedServer.D(DedicatedServer.java:399) ~[spigot-1.10.jar:git-Spigot-6016ac7-10c10b3]
at net.minecraft.server.v1_10_R1.MinecraftServer.C(MinecraftServer.java:672) ~[spigot-1.10.jar:git-Spigot-6016ac7-10c10b3]
at net.minecraft.server.v1_10_R1.MinecraftServer.run(MinecraftServer.java:571) [spigot-1.10.jar:git-Spigot-6016ac7-10c10b3]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_72]
Caused by: java.util.NoSuchElementException
at java.util.TreeMap.key(TreeMap.java:1323) ~[?:1.8.0_72]
at java.util.TreeMap.firstKey(TreeMap.java:290) ~[?:1.8.0_72]
at java.util.TreeSet.first(TreeSet.java:394) ~[?:1.8.0_72]
at org.bukkit.craftbukkit.v1_10_R1.util.HashTreeSet.first(HashTreeSet.java:114) ~[spigot-1.10.jar:git-Spigot-6016ac7-10c10b3]
at net.minecraft.server.v1_10_R1.WorldServer.a(WorldServer.java:712) ~[spigot-1.10.jar:git-Spigot-6016ac7-10c10b3]
at net.minecraft.server.v1_10_R1.WorldServer.doTick(WorldServer.java:249) ~[spigot-1.10.jar:git-Spigot-6016ac7-10c10b3]
at net.minecraft.server.v1_10_R1.MinecraftServer.D(MinecraftServer.java:788) ~[spigot-1.10.jar:git-Spigot-6016ac7-10c10b3]
... 4 more
[11:33:34] [Server thread/ERROR]: Cause of unexpected exception was
java.util.NoSuchElementException
at java.util.TreeMap.key(TreeMap.java:1323) ~[?:1.8.0_72]
at java.util.TreeMap.firstKey(TreeMap.java:290) ~[?:1.8.0_72]
at java.util.TreeSet.first(TreeSet.java:394) ~[?:1.8.0_72]
at org.bukkit.craftbukkit.v1_10_R1.util.HashTreeSet.first(HashTreeSet.java:114) ~[spigot-1.10.jar:git-Spigot-6016ac7-10c10b3]
at net.minecraft.server.v1_10_R1.WorldServer.a(WorldServer.java:712) ~[spigot-1.10.jar:git-Spigot-6016ac7-10c10b3]
at net.minecraft.server.v1_10_R1.WorldServer.doTick(WorldServer.java:249) ~[spigot-1.10.jar:git-Spigot-6016ac7-10c10b3]
at net.minecraft.server.v1_10_R1.MinecraftServer.D(MinecraftServer.java:788) ~[spigot-1.10.jar:git-Spigot-6016ac7-10c10b3]
at net.minecraft.server.v1_10_R1.DedicatedServer.D(DedicatedServer.java:399) ~[spigot-1.10.jar:git-Spigot-6016ac7-10c10b3]
at net.minecraft.server.v1_10_R1.MinecraftServer.C(MinecraftServer.java:672) ~[spigot-1.10.jar:git-Spigot-6016ac7-10c10b3]
at net.minecraft.server.v1_10_R1.MinecraftServer.run(MinecraftServer.java:571) [spigot-1.10.jar:git-Spigot-6016ac7-10c10b3]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_72]
[11:33:34] [Server thread/ERROR]: This crash report has been saved to: /var/directory_serv/minecraft_12923/./crash-reports/crash-2016-07-01_11.33.34-server.txt