extraheads -error

[09:42:54] [Server thread/ERROR]: Could not load 'plugins/ExtraHeads - DEV 8 (git 21427).jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: Cannot find main class `io.github.thebusybiscuit.extraheads.ExtraHeads'
	at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:65) ~[patched_1.15.1.jar:git-Paper-33]
	at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:134) ~[patched_1.15.1.jar:git-Paper-33]
	at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:337) ~[patched_1.15.1.jar:git-Paper-33]
	at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:257) ~[patched_1.15.1.jar:git-Paper-33]
	at org.bukkit.craftbukkit.v1_15_R1.CraftServer.loadPlugins(CraftServer.java:356) ~[patched_1.15.1.jar:git-Paper-33]
	at net.minecraft.server.v1_15_R1.DedicatedServer.init(DedicatedServer.java:226) ~[patched_1.15.1.jar:git-Paper-33]
	at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:884) ~[patched_1.15.1.jar:git-Paper-33]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_232]
Caused by: java.lang.ClassNotFoundException: io.github.thebusybiscuit.extraheads.ExtraHeads
	at java.net.URLClassLoader.findClass(URLClassLoader.java:382) ~[?:1.8.0_232]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:139) ~[patched_1.15.1.jar:git-Paper-33]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:85) ~[patched_1.15.1.jar:git-Paper-33]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:418) ~[?:1.8.0_232]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:351) ~[?:1.8.0_232]
	at java.lang.Class.forName0(Native Method) ~[?:1.8.0_232]
	at java.lang.Class.forName(Class.java:348) ~[?:1.8.0_232]
	at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:63) ~[patched_1.15.1.jar:git-Paper-33]
	... 7 more