NullPointerException at server startup

java -Xms1G -Xmx2G -d64 -jar minecraft_server.jar nogui

---- Minecraft Crash Report ----
// On the bright side, I bought you a teddy bear!

Time: 9/14/16 10:42 AM
Description: Exception in server tick loop

java.lang.NullPointerException: Exception in server tick loop
at mt.g(SourceFile:144)
at lc.z(SourceFile:99)
at lc.<init>(SourceFile:25)
at ld.j(SourceFile:185)
at net.minecraft.server.MinecraftServer.run(SourceFile:428)
at java.lang.Thread.run(Thread.java:745)