Factions error

[10:04:30] [Server thread/INFO]: [Factions 2.8.21] === ENABLE START ===
[10:04:30] [Server thread/ERROR]: Error occurred while enabling Factions v2.8.21 (Is it up to date?)
java.lang.RuntimeException: Failed to create a flatfile system pusher.
	at com.massivecraft.massivecore.store.DriverFlatfile.getPusher(DriverFlatfile.java:268) ~[?:?]
	at com.massivecraft.massivecore.store.DbAbstract.getPusher(DbAbstract.java:87) ~[?:?]
	at com.massivecraft.massivecore.store.Coll.getPusher(Coll.java:111) ~[?:?]
	at com.massivecraft.massivecore.store.Coll.setActive(Coll.java:1069) ~[?:?]
	at com.massivecraft.factions.Factions.onEnableInner(Factions.java:138) ~[?:?]
	at com.massivecraft.massivecore.MassivePlugin.onEnable(MassivePlugin.java:75) ~[?:?]
	at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:271) ~[custom.jar:git-Spigot-0f17cfb-a0d5a84]
	at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:337) [custom.jar:git-Spigot-0f17cfb-a0d5a84]
	at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:405) [custom.jar:git-Spigot-0f17cfb-a0d5a84]
	at org.bukkit.craftbukkit.v1_11_R1.CraftServer.enablePlugin(CraftServer.java:375) [custom.jar:git-Spigot-0f17cfb-a0d5a84]
	at org.bukkit.craftbukkit.v1_11_R1.CraftServer.enablePlugins(CraftServer.java:325) [custom.jar:git-Spigot-0f17cfb-a0d5a84]
	at net.minecraft.server.v1_11_R1.MinecraftServer.t(MinecraftServer.java:419) [custom.jar:git-Spigot-0f17cfb-a0d5a84]
	at net.minecraft.server.v1_11_R1.MinecraftServer.l(MinecraftServer.java:380) [custom.jar:git-Spigot-0f17cfb-a0d5a84]
	at net.minecraft.server.v1_11_R1.MinecraftServer.a(MinecraftServer.java:335) [custom.jar:git-Spigot-0f17cfb-a0d5a84]
	at net.minecraft.server.v1_11_R1.DedicatedServer.init(DedicatedServer.java:272) [custom.jar:git-Spigot-0f17cfb-a0d5a84]
	at net.minecraft.server.v1_11_R1.MinecraftServer.run(MinecraftServer.java:542) [custom.jar:git-Spigot-0f17cfb-a0d5a84]
	at java.lang.Thread.run(Unknown Source) [?:1.8.0_65]
Caused by: java.io.IOException: User limit of inotify instances reached or too many open files
	at sun.nio.fs.LinuxWatchService.<init>(Unknown Source) ~[?:1.8.0_65]
	at sun.nio.fs.LinuxFileSystem.newWatchService(Unknown Source) ~[?:1.8.0_65]
	at com.massivecraft.massivecore.store.PusherCollFlatfile.<init>(PusherCollFlatfile.java:217) ~[?:?]
	at com.massivecraft.massivecore.store.DriverFlatfile.getPusher(DriverFlatfile.java:264) ~[?:?]
	... 16 more