Instead of calling getCustomName() to get the player name for web entities, especially since custom names can be disabled or unsupported, should probably use a map from entity id to web client username:
04:56:20 [WARNING] [WebSandboxMC] Task #30 for WebSandboxMC v0.7 generated an exception
java.lang.NoSuchMethodError: org.bukkit.entity.Entity.getCustomName()Ljava/lang/String;
at io.github.satoshinm.WebSandboxMC.bridge.PlayersBridge.sendPlayers(PlayersBridge.java:66)
at io.github.satoshinm.WebSandboxMC.ws.WebSocketServerThread.handleNewClient(WebSocketServerThread.java:181)
at io.github.satoshinm.WebSandboxMC.ws.WebSocketFrameHandler$1.run(WebSocketFrameHandler.java:47)
at org.bukkit.craftbukkit.v1_5_R3.scheduler.CraftTask.run(CraftTask.java:58)
at org.bukkit.craftbukkit.v1_5_R3.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:344)
at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:777)
at net.minecraft.server.dedicated.DedicatedServer.func_71190_q(DedicatedServer.java:320)
at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:732)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:614)
at net.minecraft.server.ThreadMinecraftServer.run(SourceFile:573)
Instead of calling getCustomName() to get the player name for web entities, especially since custom names can be disabled or unsupported, should probably use a map from entity id to web client username: