Skill issue

[Memexurer]

[12:26:37] [Craft Scheduler Thread - 2/WARN]: org.apache.commons.lang.UnhandledException: Plugin BedWarsProxy v${gitVer}1.2.4 generated an exception while executing task 12
	at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:56)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
	at java.base/java.lang.Thread.run(Thread.java:831)
Caused by: java.lang.NullPointerException: Nodes must be provided.
	at org.yaml.snakeyaml.nodes.NodeTuple.<init>(NodeTuple.java:28)
	at org.yaml.snakeyaml.representer.BaseRepresenter.representMapping(BaseRepresenter.java:164)
	at org.yaml.snakeyaml.representer.SafeRepresenter$RepresentMap.representData(SafeRepresenter.java:315)
	at org.yaml.snakeyaml.representer.BaseRepresenter.representData(BaseRepresenter.java:95)
	at org.yaml.snakeyaml.representer.BaseRepresenter.represent(BaseRepresenter.java:65)
	at org.yaml.snakeyaml.Yaml.dumpAll(Yaml.java:307)
	at org.yaml.snakeyaml.Yaml.dumpAll(Yaml.java:271)
	at org.yaml.snakeyaml.Yaml.dump(Yaml.java:246)
	at org.bukkit.configuration.file.YamlConfiguration.saveToString(YamlConfiguration.java:40)
	at org.bukkit.configuration.file.FileConfiguration.save(FileConfiguration.java:103)
	at com.andrei1058.bedwars.proxy.configuration.PluginConfig.save(PluginConfig.java:162)
	at com.andrei1058.bedwars.proxy.configuration.PluginConfig.set(PluginConfig.java:147)
	at com.andrei1058.bedwars.proxy.language.LanguageManager.saveIfNotExists(LanguageManager.java:56)
	at com.andrei1058.bedwars.proxy.arenamanager.LegacyArena.<init>(LegacyArena.java:47)
	at com.andrei1058.bedwars.proxy.arenamanager.LegacyArena.<init>(LegacyArena.java:51)
	at com.andrei1058.bedwars.proxy.socketmanager.ArenaSocketTask.run(ArenaSocketTask.java:124)
	at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftTask.run(CraftTask.java:71)
	at org.bukkit.craftbukkit.v1_8_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
	... 3 more