[00:21:57] [Server thread/INFO]: [WorldBorder] [Fill] 25856 more chunks processed (150016 total, ~20.6%) (free mem: 3993 MB)
[00:22:00] [Server thread/WARN]: [WorldBorder] Task #16 for WorldBorder v1.9.10 (beta) generated an exception
java.lang.NoClassDefFoundError: io/papermc/lib/PaperLib
	at com.wimbli.WorldBorder.WorldFillTask.run(WorldFillTask.java:319) ~[?:?]
	at org.bukkit.craftbukkit.v1_15_R1.scheduler.CraftTask.run(CraftTask.java:84) ~[patched_1.15.2.jar:git-Paper-77]
	at org.bukkit.craftbukkit.v1_15_R1.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:452) ~[patched_1.15.2.jar:git-Paper-77]
	at net.minecraft.server.v1_15_R1.MinecraftServer.b(MinecraftServer.java:1185) ~[patched_1.15.2.jar:git-Paper-77]
	at net.minecraft.server.v1_15_R1.DedicatedServer.b(DedicatedServer.java:423) ~[patched_1.15.2.jar:git-Paper-77]
	at net.minecraft.server.v1_15_R1.MinecraftServer.a(MinecraftServer.java:1112) ~[patched_1.15.2.jar:git-Paper-77]
	at net.minecraft.server.v1_15_R1.MinecraftServer.run(MinecraftServer.java:934) ~[patched_1.15.2.jar:git-Paper-77]
	at java.lang.Thread.run(Thread.java:748) [?:1.8.0_232]
Caused by: java.lang.ClassNotFoundException: io.papermc.lib.PaperLib
	at java.net.URLClassLoader.findClass(URLClassLoader.java:382) ~[?:1.8.0_232]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:150) ~[patched_1.15.2.jar:git-Paper-77]
	at org.bukkit.plugin.java.PluginClassLoader.findClass(PluginClassLoader.java:96) ~[patched_1.15.2.jar:git-Paper-77]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:418) ~[?:1.8.0_232]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:351) ~[?:1.8.0_232]
	... 8 more