Bukkit

What steps will reproduce the problem?
1.I set the highest health level of player to 30(15 Hearts)
2.I am an op. When the highest health level of me is under the player( like my health:10 hearts,player:15 hearts)
3.The server say I got the internal error.

What is the expected output? What do you see instead?

What version of the product are you using?

Spectate V2.1 for 1.7.2

Do you have an error log of what happened?

2016/1/29 下午 11:50:49 [INFO] oldmiow issued server command: /spec oldmiowtest
2016/1/29 下午 11:50:49 [SEVERE] null
2016/1/29 下午 11:50:49 org.bukkit.command.CommandException: Unhandled exception executing command 'spec' in plugin Spectate v2.0
2016/1/29 下午 11:50:49     at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50     at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:175) ~[spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50     at org.bukkit.craftbukkit.v1_7_R1.CraftServer.dispatchCommand(CraftServer.java:706) ~[spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50     at net.minecraft.server.v1_7_R1.PlayerConnection.handleCommand(PlayerConnection.java:984) [spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50     at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java:829) [spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50     at com.bergerkiller.bukkit.common.internal.network.CommonPacketHandler$CommonPlayerConnection.a(CommonPacketHandler.java:244) [BKCommonLib-1.57.jar:?]
2016/1/29 下午 11:50:50     at net.minecraft.server.v1_7_R1.PacketPlayInChat.a(PacketPlayInChat.java:28) [spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50     at net.minecraft.server.v1_7_R1.PacketPlayInChat.handle(PacketPlayInChat.java:65) [spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50     at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:147) [spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50     at net.minecraft.server.v1_7_R1.ServerConnection.c(ServerConnection.java:77) [spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50     at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:700) [spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50     at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:273) [spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50     at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:562) [spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50     at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:469) [spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50     at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50 Caused by: java.lang.IllegalArgumentException: Health must be between 0 and 20.0
2016/1/29 下午 11:50:50     at org.bukkit.craftbukkit.v1_7_R1.entity.CraftLivingEntity.setHealth(CraftLivingEntity.java:81) ~[spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50     at com.Chipmunk9998.Spectate.api.SpectateManager.startSpectating(SpectateManager.java:235) ~[?:?]
2016/1/29 下午 11:50:50     at com.Chipmunk9998.Spectate.SpectateCommandExecutor.onCommand(SpectateCommandExecutor.java:324) ~[?:?]
2016/1/29 下午 11:50:50     at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[spigot-1.7.2-R0.4-SNAPSHOT.jar:git-Spigot-1.7.2-R0.3-122-gb58e277]
2016/1/29 下午 11:50:50     ... 14 more

Please provide any additional information below.
I use levelhearts-v1.2.0 to set health function,server is spigot 1.7.2 R0.3,but the same problem also happen in bukkit 1.7.2