java.lang.RuntimeException: java.lang.IllegalArgumentException: Tried to get block runtime id for unsupported protocol version: 20
        at cn.nukkit.plugin.PluginManager.enablePlugin(PluginManager.java:408) [Nukkit-PM1E.jar:?]
        at cn.nukkit.Server.enablePlugin(Server.java:689) [Nukkit-PM1E.jar:?]
        at cn.nukkit.Server.enablePlugins(Server.java:679) [Nukkit-PM1E.jar:?]
        at cn.nukkit.Server.<init>(Server.java:421) [Nukkit-PM1E.jar:?]
        at cn.nukkit.Nukkit.main(Nukkit.java:78) [Nukkit-PM1E.jar:?]
Caused by: java.lang.IllegalArgumentException: Tried to get block runtime id for unsupported protocol version: 20
        at cn.nukkit.level.GlobalBlockPalette.getOrCreateRuntimeId(GlobalBlockPalette.java:409) ~[Nukkit-PM1E.jar:?]
        at cn.nukkit.level.GlobalBlockPalette.getOrCreateRuntimeId(GlobalBlockPalette.java:510) ~[Nukkit-PM1E.jar:?]
        at Sergey_Dertan.SRegionProtector.Region.Selector.RegionSelector.<init>(RegionSelector.java:33) ~[?:?]
        at Sergey_Dertan.SRegionProtector.Main.SRegionProtectorMain.initRegions(SRegionProtectorMain.java:199) ~[?:?]
        at Sergey_Dertan.SRegionProtector.Main.SRegionProtectorMain.onEnable(SRegionProtectorMain.java:96) ~[?:?]
        at cn.nukkit.plugin.PluginBase.setEnabled(PluginBase.java:89) ~[Nukkit-PM1E.jar:?]
        at cn.nukkit.plugin.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:119) ~[Nukkit-PM1E.jar:?]
        at cn.nukkit.plugin.PluginManager.enablePlugin(PluginManager.java:404) ~[Nukkit-PM1E.jar:?]
        ... 4 more
14:47:42 [INFO ] Disabling SRegionProtector v30.0
14:47:42 [INFO ] [SRegionProtector] Starting saving...
14:47:42 [ERROR] Throwing
java.lang.NullPointerException: null
        at Sergey_Dertan.SRegionProtector.Main.SRegionProtectorMain.save(SRegionProtectorMain.java:239) ~[?:?]
        at Sergey_Dertan.SRegionProtector.Main.SRegionProtectorMain.save(SRegionProtectorMain.java:224) ~[?:?]
        at Sergey_Dertan.SRegionProtector.Main.SRegionProtectorMain.onDisable(SRegionProtectorMain.java:421) ~[?:?]
        at cn.nukkit.plugin.PluginBase.setEnabled(PluginBase.java:91) ~[Nukkit-PM1E.jar:?]
        at cn.nukkit.plugin.JavaPluginLoader.disablePlugin(JavaPluginLoader.java:134) ~[Nukkit-PM1E.jar:?]
        at cn.nukkit.plugin.PluginManager.disablePlugin(PluginManager.java:479) [Nukkit-PM1E.jar:?]
        at cn.nukkit.plugin.PluginManager.enablePlugin(PluginManager.java:410) [Nukkit-PM1E.jar:?]
        at cn.nukkit.Server.enablePlugin(Server.java:689) [Nukkit-PM1E.jar:?]
        at cn.nukkit.Server.enablePlugins(Server.java:679) [Nukkit-PM1E.jar:?]
        at cn.nukkit.Server.<init>(Server.java:421) [Nukkit-PM1E.jar:?]
        at cn.nukkit.Nukkit.main(Nukkit.java:78) [Nukkit-PM1E.jar:?]