When i do "/holo edit hologram"
it say "An internal error occured while attempting to perform this command"
My server is 1.8 CraftBukkit

Version of the plugin? Can you paste the error on the console (on pastebin if possible)?

[12:55:52] [Server thread/INFO]: NightIGhost issued server command: /holo edit welcome [12:55:52] [Server thread/ERROR]: null org.bukkit.command.CommandException: Unhandled exception executing command 'holo' in plugin HolographicDisplays v2.3.2 at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[minecraft_server.jar:git-Bukkit-7019900] at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:140) ~[minecraft_server.jar:git-Bukkit-7019900] at org.bukkit.craftbukkit.v1_8_R1.CraftServer.dispatchCommand(CraftServer.java:625) ~[minecraft_server.jar:git-Bukkit-7019900] at net.minecraft.server.v1_8_R1.PlayerConnection.handleCommand(PlayerConnection.java:1058) [minecraft_server.jar:git-Bukkit-7019900] at net.minecraft.server.v1_8_R1.PlayerConnection.a(PlayerConnection.java:919) [minecraft_server.jar:git-Bukkit-7019900] at net.minecraft.server.v1_8_R1.PacketPlayInChat.a(SourceFile:37) [minecraft_server.jar:git-Bukkit-7019900] at net.minecraft.server.v1_8_R1.PacketPlayInChat.a(SourceFile:9) [minecraft_server.jar:git-Bukkit-7019900] at net.minecraft.server.v1_8_R1.PacketHandleTask.run(SourceFile:13) [minecraft_server.jar:git-Bukkit-7019900] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_202] at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_202] at net.minecraft.server.v1_8_R1.MinecraftServer.z(MinecraftServer.java:656) [minecraft_server.jar:git-Bukkit-7019900] at net.minecraft.server.v1_8_R1.DedicatedServer.z(DedicatedServer.java:284) [minecraft_server.jar:git-Bukkit-7019900] at net.minecraft.server.v1_8_R1.MinecraftServer.y(MinecraftServer.java:609) [minecraft_server.jar:git-Bukkit-7019900] at net.minecraft.server.v1_8_R1.MinecraftServer.run(MinecraftServer.java:517) [minecraft_server.jar:git-Bukkit-7019900] at java.lang.Thread.run(Thread.java:748) [?:1.8.0_202] Caused by: java.lang.NoSuchMethodError: org.bukkit.entity.Player.spigot()Lorg/bukkit/entity/Player$Spigot; at com.gmail.filoghost.holographicdisplays.commands.main.subs.EditCommand.execute(EditCommand.java:80) ~[?:?] at com.gmail.filoghost.holographicdisplays.commands.main.HologramsCommandHandler.onCommand(HologramsCommandHandler.java:107) ~[?:?] at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[minecraft_server.jar:git-Bukkit-7019900] ... 14 more

Use Spigot instead of CraftBukkit.