No crash report generated. Server shutdown after Error encountered.
Log provided:

[21:17:02] [Server thread/INFO]: Saving...
[21:17:02] [Server thread/INFO]: Saved the world
[21:19:43] [Server thread/INFO]: com.mojang.authlib.GameProfile@45202f70[id=<null>,name=MCI,properties={},legacy=false] (/198.27.83.157:37514) lost connection: Internal Exception: java.io.IOException: Connection reset by peer
[21:27:02] [Server thread/INFO]: Saving...
[21:27:02] [Server thread/INFO]: Saved the world
[21:29:50] [Server thread/INFO]: com.mojang.authlib.GameProfile@26567f45[id=<null>,name=MCI,properties={},legacy=false] (/198.27.83.157:49436) lost connection: Internal Exception: java.io.IOException: Connection reset by peer
[21:30:32] [Server thread/ERROR]: Encountered an unexpected exception
java.lang.NoClassDefFoundError: Could not initialize class b
at net.minecraft.server.MinecraftServer.x(SourceFile:580) ~[minecraft_server.jar:?]
at pf.x(SourceFile:297) ~[minecraft_server.jar:?]
at net.minecraft.server.MinecraftServer.w(SourceFile:510) ~[minecraft_server.jar:?]
at net.minecraft.server.MinecraftServer.run(SourceFile:426) [minecraft_server.jar:?]
at java.lang.Thread.run(Unknown Source) [?:1.7.0_01]
[21:30:32] [Server thread/INFO]: Stopping server
[21:30:32] [Server thread/INFO]: Saving players
[21:30:32] [Server thread/INFO]: Saving worlds
[21:30:32] [Server thread/INFO]: Saving chunks for level 'world'/Overworld
[21:30:32] [Server thread/INFO]: Saving chunks for level 'world'/Nether
[21:30:32] [Server thread/INFO]: Saving chunks for level 'world'/The End
[21:30:33] [Server Shutdown Thread/INFO]: Stopping server