Erreur start plugin

[18:11:35 INFO]: [MineDream_Plugin_API] Enabling MineDream_Plugin_API v1.0
[18:11:35 ERROR]: Error occurred while enabling MineDream_Plugin_API v1.0 (Is it up to date?)
java.lang.NoClassDefFoundError: fr/izumiofficiel/minedreamattrac/SqlConnection
    at fr.izumiofficiel.minedreamattrac.Principal.onEnable(Principal.java:82) ~[?:?]
    at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:254) ~[server.jar:git-Spigot-29ab5e4-2bc7d1d]
    at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:340) [server.jar:git-Spigot-29ab5e4-2bc7d1d]
    at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:403) [server.jar:git-Spigot-29ab5e4-2bc7d1d]
    at org.bukkit.craftbukkit.v1_13_R2.CraftServer.enablePlugin(CraftServer.java:434) [server.jar:git-Spigot-29ab5e4-2bc7d1d]
    at org.bukkit.craftbukkit.v1_13_R2.CraftServer.enablePlugins(CraftServer.java:348) [server.jar:git-Spigot-29ab5e4-2bc7d1d]
    at net.minecraft.server.v1_13_R2.MinecraftServer.l(MinecraftServer.java:579) [server.jar:git-Spigot-29ab5e4-2bc7d1d]
    at net.minecraft.server.v1_13_R2.MinecraftServer.a(MinecraftServer.java:541) [server.jar:git-Spigot-29ab5e4-2bc7d1d]
    at net.minecraft.server.v1_13_R2.MinecraftServer.a(MinecraftServer.java:419) [server.jar:git-Spigot-29ab5e4-2bc7d1d]
    at net.minecraft.server.v1_13_R2.DedicatedServer.init(DedicatedServer.java:294) [server.jar:git-Spigot-29ab5e4-2bc7d1d]
    at net.minecraft.server.v1_13_R2.MinecraftServer.run(MinecraftServer.java:697) [server.jar:git-Spigot-29ab5e4-2bc7d1d]
    at java.lang.Thread.run(Thread.java:748) [?:1.8.0_181]
Caused by: java.lang.ClassNotFoundException: fr.izumiofficiel.minedreamattrac.SqlConnection
    at java.net.URLClassLoader.findClass(URLClassLoader.java:382) ~[?:1.8.0_181]
    at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:134) ~[server.jar:git-Spigot-29ab5e4-2bc7d1d]
    at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:80) ~[server.jar:git-Spigot-29ab5e4-2bc7d1d]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[?:1.8.0_181]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[?:1.8.0_181]
    ... 12 more