Hello! There was a problem: when trying to lock the 4th region it does not allow to do this, although in the config set:
max-region-count-per-player: default: 3 fly: 4 vip: 5 creative: 6 premium: 8 king: 10 god: 20
An error appears in the console:
[14:12:12 WARN]: java.lang.UnsupportedOperationException: SuperPerms no group permissions. [14:12:12 WARN]: at net.milkbowl.vault.permission.plugins.Permission_SuperPerms.getPlayerGroups(Permission_SuperPerms.java:91) [14:12:12 WARN]: at net.milkbowl.vault.permission.Permission.getPlayerGroups(Permission.java:637) [14:12:12 WARN]: at net.milkbowl.vault.permission.Permission.getPlayerGroups(Permission.java:649) [14:12:12 WARN]: at com.sk89q.wepif.VaultResolver.getGroups(VaultResolver.java:115) [14:12:12 WARN]: at com.sk89q.wepif.PermissionsResolverManager.getGroups(PermissionsResolverManager.java:180) [14:12:12 WARN]: at com.sk89q.worldguard.bukkit.WorldGuardPlugin.getGroups(WorldGuardPlugin.java:330) [14:12:12 WARN]: at com.sk89q.worldguard.bukkit.BukkitPlayer.getGroups(BukkitPlayer.java:207) [14:12:12 WARN]: at com.sk89q.worldguard.config.WorldConfiguration.getMaxRegionCount(WorldConfiguration.java:247) [14:12:12 WARN]: at com.sk89q.worldguard.commands.region.RegionCommands.claim(RegionCommands.java:266) [14:12:12 WARN]: at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [14:12:12 WARN]: at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) [14:12:12 WARN]: at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) [14:12:12 WARN]: at java.lang.reflect.Method.invoke(Unknown Source) [14:12:12 WARN]: at com.sk89q.minecraft.util.commands.CommandsManager.invokeMethod(CommandsManager.java:526) [14:12:12 WARN]: at com.sk89q.minecraft.util.commands.CommandsManager.executeMethod(CommandsManager.java:514) [14:12:12 WARN]: at com.sk89q.minecraft.util.commands.CommandsManager.executeMethod(CommandsManager.java:469) [14:12:12 WARN]: at com.sk89q.minecraft.util.commands.CommandsManager.execute(CommandsManager.java:407) [14:12:12 WARN]: at com.sk89q.worldguard.bukkit.WorldGuardPlugin.onCommand(WorldGuardPlugin.java:273) [14:12:12 WARN]: at com.sk89q.bukkit.util.DynamicPluginCommand.execute(DynamicPluginCommand.java:54) [14:12:12 WARN]: at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:159) [14:12:12 WARN]: at org.bukkit.craftbukkit.v1_16_R1.CraftServer.dispatchCommand(CraftServer.java:794) [14:12:12 WARN]: at net.minecraft.server.v1_16_R1.PlayerConnection.handleCommand(PlayerConnection.java:1908) [14:12:12 WARN]: at net.minecraft.server.v1_16_R1.PlayerConnection.a(PlayerConnection.java:1719) [14:12:12 WARN]: at net.minecraft.server.v1_16_R1.PacketPlayInChat.a(PacketPlayInChat.java:47) [14:12:12 WARN]: at net.minecraft.server.v1_16_R1.PacketPlayInChat.a(PacketPlayInChat.java:5) [14:12:12 WARN]: at net.minecraft.server.v1_16_R1.PlayerConnectionUtils.lambda$ensureMainThread$0(PlayerConnectionUtils.java:23) [14:12:12 WARN]: at net.minecraft.server.v1_16_R1.TickTask.run(SourceFile:18) [14:12:12 WARN]: at net.minecraft.server.v1_16_R1.IAsyncTaskHandler.executeTask(IAsyncTaskHandler.java:136) [14:12:12 WARN]: at net.minecraft.server.v1_16_R1.IAsyncTaskHandlerReentrant.executeTask(SourceFile:23) [14:12:12 WARN]: at net.minecraft.server.v1_16_R1.IAsyncTaskHandler.executeNext(IAsyncTaskHandler.java:109) [14:12:12 WARN]: at net.minecraft.server.v1_16_R1.MinecraftServer.aZ(MinecraftServer.java:1136) [14:12:12 WARN]: at net.minecraft.server.v1_16_R1.MinecraftServer.executeNext(MinecraftServer.java:1129) [14:12:12 WARN]: at net.minecraft.server.v1_16_R1.IAsyncTaskHandler.awaitTasks(IAsyncTaskHandler.java:119) [14:12:12 WARN]: at net.minecraft.server.v1_16_R1.MinecraftServer.sleepForTick(MinecraftServer.java:1090) [14:12:12 WARN]: at net.minecraft.server.v1_16_R1.MinecraftServer.v(MinecraftServer.java:1004) [14:12:12 WARN]: at net.minecraft.server.v1_16_R1.MinecraftServer.lambda$a$0(MinecraftServer.java:177) [14:12:12 WARN]: at java.lang.Thread.run(Unknown Source)

Permissions plugin - LuckPerms, group - fly
Vault installed
Paper 1.16.
How to fix?

worldguard attempted to use a group lookup via Vault SuperPerms to find group permissions (which isn't supported). When it should be attempting a lookup in LuckPerms (if it's actually installed). Worldguard perhaps isn't detecting you have luckperms installed, or perhaps there's an incompatibility in here somewhere with timing (out of order detection of permission system). Either way, not a Vault issue.