: Could not load 'plugins\CommandsSigns.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: Cannot find main class `me.itsazeel.Tutorial4.Tutorial4'
        at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:80) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
        at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:129) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
        at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:327) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
        at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:248) [spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
        at org.bukkit.craftbukkit.v1_12_R1.CraftServer.loadPlugins(CraftServer.java:305) [spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
        at net.minecraft.server.v1_12_R1.DedicatedServer.init(DedicatedServer.java:205) [spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
        at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:545) [spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_221]
Caused by: java.lang.ClassNotFoundException: me.itsazeel.Tutorial4.Tutorial4
        at java.net.URLClassLoader.findClass(Unknown Source) ~[?:1.8.0_221]
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:152) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
        at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:100) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]
        at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_221]
        at java.lang.ClassLoader.loadClass(Unknown Source) ~[?:1.8.0_221]
        at java.lang.Class.forName0(Native Method) ~[?:1.8.0_221]
        at java.lang.Class.forName(Unknown Source) ~[?:1.8.0_221]
        at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:78) ~[spigot-1.12.2.jar:git-Spigot-dcd1643-e60fc34]