Can't start plugin

[FyzzyDogos]

[20:21:36 ERROR]: Error occurred while enabling PackStacker v1.1.0 (Is it up to date?)
java.lang.NullPointerException: Cannot read the array length because "elements" is null
at java.base/java.util.List.of(List.java:1162) ~[?:?]
at PackStacker-Bukkit-1.0.4.jar/com.timomcgrath.packstacker.FileLoader.getPackConfigurations(FileLoader.java:76) ~[PackStacker-Bukkit-1.0.4.jar:?]
at PackStacker-Bukkit-1.0.4.jar/com.timomcgrath.packstacker.FileLoader.loadPacks(FileLoader.java:67) ~[PackStacker-Bukkit-1.0.4.jar:?]
at PackStacker-Bukkit-1.0.4.jar/com.timomcgrath.packstacker.PackStacker.reloadAll(PackStacker.java:71) ~[PackStacker-Bukkit-1.0.4.jar:?]
at PackStacker-Bukkit-1.0.4.jar/com.timomcgrath.packstacker.PackStacker.onEnable(PackStacker.java:45) ~[PackStacker-Bukkit-1.0.4.jar:?]
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:288) ~[paper-mojangapi-1.21.1-R0.1-SNAPSHOT.jar:?]
at io.papermc.paper.plugin.manager.PaperPluginInstanceManager.enablePlugin(PaperPluginInstanceManager.java:202) ~[leaf-1.21.1.jar:1.21.1-DEV-d6b323a]
at io.papermc.paper.plugin.manager.PaperPluginManagerImpl.enablePlugin(PaperPluginManagerImpl.java:109) ~[leaf-1.21.1.jar:1.21.1-DEV-d6b323a]
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:519) ~[paper-mojangapi-1.21.1-R0.1-SNAPSHOT.jar:?]
at org.bukkit.craftbukkit.CraftServer.enablePlugin(CraftServer.java:658) ~[leaf-1.21.1.jar:1.21.1-DEV-d6b323a]
at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:607) ~[leaf-1.21.1.jar:1.21.1-DEV-d6b323a]
at net.minecraft.server.MinecraftServer.loadWorld0(MinecraftServer.java:742) ~[leaf-1.21.1.jar:1.21.1-DEV-d6b323a]
at net.minecraft.server.MinecraftServer.loadLevel(MinecraftServer.java:504) ~[leaf-1.21.1.jar:1.21.1-DEV-d6b323a]
at net.minecraft.server.dedicated.DedicatedServer.initServer(DedicatedServer.java:374) ~[leaf-1.21.1.jar:1.21.1-DEV-d6b323a]
at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:1216) ~[leaf-1.21.1.jar:1.21.1-DEV-d6b323a]
at net.minecraft.server.MinecraftServer.lambda$spin$0(MinecraftServer.java:319) ~[leaf-1.21.1.jar:1.21.1-DEV-d6b323a]
at java.base/java.lang.Thread.run(Thread.java:1583) ~[?:?]