出现问题,怎么解决?

16:10:45 [INFO] 读取中... PlotSquared v3.5.1-SNAPSHOT-c8c144b
16:10:45 [INFO] 开启中... PlotSquared v3.5.1-SNAPSHOT-c8c144b
> java.lang.NoClassDefFoundError: com/boydti/fawe/yaml/representer/Representer
at com.intellectualcrafters.plot.PS.setupConfigs(PS.java:1911)
at com.intellectualcrafters.plot.PS.<init>(PS.java:155)
at com.plotsquared.nukkit.NukkitMain.onEnable(NukkitMain.java:101)
at cn.nukkit.plugin.PluginBase.setEnabled(PluginBase.java:89)
at cn.nukkit.plugin.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:119)
at cn.nukkit.plugin.PluginManager.enablePlugin(PluginManager.java:446)
at cn.nukkit.Server.enablePlugin(Server.java:628)
at cn.nukkit.Server.enablePlugins(Server.java:617)
at cn.nukkit.Server.<init>(Server.java:391)
at cn.nukkit.Nukkit.main(Nukkit.java:68)
Caused by: java.lang.ClassNotFoundException: com.boydti.fawe.yaml.representer.Representer
at java.net.URLClassLoader.findClass(Unknown Source)
at cn.nukkit.plugin.PluginClassLoader.findClass(PluginClassLoader.java:44)
at cn.nukkit.plugin.PluginClassLoader.findClass(PluginClassLoader.java:28)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 10 more