[17:00:56] [Server thread/WARN]: org.bukkit.plugin.IllegalPluginAccessException: java.lang.NullPointerException [17:00:56] [Server thread/WARN]: at org.bukkit.plugin.SimplePluginManager.getEventListeners(SimplePluginManager.java:569) [17:00:56] [Server thread/WARN]: at org.bukkit.plugin.SimplePluginManager.registerEvents(SimplePluginManager.java:525) [17:00:56] [Server thread/WARN]: at io.github.steve4744.ParkourTopTen.ParkourTopTen.reload(ParkourTopTen.java:84) [17:00:56] [Server thread/WARN]: at io.github.steve4744.ParkourTopTen.ParkourTopTen$1.run(ParkourTopTen.java:41) [17:00:56] [Server thread/WARN]: at org.bukkit.craftbukkit.v1_12_R1.scheduler.CraftTask.run(CraftTask.java:71) [17:00:56] [Server thread/WARN]: at org.bukkit.craftbukkit.v1_12_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:353) [17:00:56] [Server thread/WARN]: at net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:738) [17:00:56] [Server thread/WARN]: at net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:405) [17:00:56] [Server thread/WARN]: at net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:678) [17:00:56] [Server thread/WARN]: at net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:576) [17:00:56] [Server thread/WARN]: at java.lang.Thread.run(Thread.java:745)

According to https://hub.spigotmc.org/jira/browse/SPIGOT-308

Event classes require a static getHandlerList() method in order to work, this is a "feature" of the event system bukkit uses.