I'm not a dummy, so I've checked these

• I am not using any other permission management plugin
• I use the latest available version of PowerRanks
• I am a human

Describe the bug
Looks like some funky stuff is happening in PowerPermissibleBase

To Reproduce
Steps to reproduce the behavior:

1. Unknown

Logs

[10:37:09 ERROR]: --- DO NOT REPORT THIS TO PAPER - THIS IS NOT A BUG OR A CRASH ---
[10:37:10 ERROR]: The server has not responded for 0 seconds! Creating thread dump
[10:37:10 ERROR]: ------------------------------
[10:37:10 ERROR]: Server thread dump (Look for plugins here before reporting to Paper!):
[10:37:10 ERROR]: ------------------------------
[10:37:10 ERROR]: Current Thread: Server thread
[10:37:10 ERROR]: PID: 22 | Suspended: false | Native: false | State: RUNNABLE
[10:37:10 ERROR]: Stack:
[10:37:10 ERROR]: org.bukkit.permissions.PermissibleBase.calculateChildPermissions(PermissibleBase.java:190)
[10:37:10 ERROR]: org.bukkit.permissions.PermissibleBase.calculateChildPermissions(PermissibleBase.java:196)
[10:37:10 ERROR]: org.bukkit.permissions.PermissibleBase.recalculatePermissions(PermissibleBase.java:163)
[10:37:10 ERROR]: nl.svenar.PowerRanks.Data.PowerPermissibleBase.recalculatePermissions(PowerPermissibleBase.java:88)
[10:37:10 ERROR]: org.bukkit.craftbukkit.v1_12_R1.entity.CraftHumanEntity.recalculatePermissions(CraftHumanEntity.java:140)
[10:37:10 ERROR]: nl.svenar.PowerRanks.PowerRanks.getEffectivePlayerPermissions(PowerRanks.java:941)
[10:37:10 ERROR]: nl.svenar.PowerRanks.Data.PowerPermissibleBase.hasPermission(PowerPermissibleBase.java:40)
[10:37:10 ERROR]: org.bukkit.craftbukkit.v1_12_R1.entity.CraftHumanEntity.hasPermission(CraftHumanEntity.java:112)
[10:37:10 ERROR]: org.bukkit.command.Command.testPermissionSilent(Command.java:207)
[10:37:10 ERROR]: org.bukkit.command.SimpleCommandMap.tabComplete(SimpleCommandMap.java:201)
[10:37:10 ERROR]: org.bukkit.command.SimpleCommandMap.tabComplete(SimpleCommandMap.java:183)
[10:37:10 ERROR]: org.bukkit.craftbukkit.v1_12_R1.CraftServer.tabCompleteCommand(CraftServer.java:1696)
[10:37:10 ERROR]: org.bukkit.craftbukkit.v1_12_R1.CraftServer.tabComplete(CraftServer.java:1670)
[10:37:10 ERROR]: net.minecraft.server.v1_12_R1.MinecraftServer.tabCompleteCommand(MinecraftServer.java:1232)
[10:37:10 ERROR]: net.minecraft.server.v1_12_R1.PlayerConnection$9.evaluate(PlayerConnection.java:2332)
[10:37:10 ERROR]: net.minecraft.server.v1_12_R1.PlayerConnection$9.evaluate(PlayerConnection.java:2329)
[10:37:10 ERROR]: org.bukkit.craftbukkit.v1_12_R1.util.Waitable.run(Waitable.java:24)
[10:37:10 ERROR]: net.minecraft.server.v1_12_R1.MinecraftServer.D(MinecraftServer.java:861)
[10:37:10 ERROR]: net.minecraft.server.v1_12_R1.DedicatedServer.D(DedicatedServer.java:423)
[10:37:10 ERROR]: net.minecraft.server.v1_12_R1.MinecraftServer.C(MinecraftServer.java:774)
[10:37:10 ERROR]: net.minecraft.server.v1_12_R1.MinecraftServer.run(MinecraftServer.java:666)
[10:37:10 ERROR]: java.lang.Thread.run(Thread.java:748)
[10:37:10 ERROR]: ------------------------------
[10:37:10 ERROR]: --- DO NOT REPORT THIS TO PAPER - THIS IS NOT A BUG OR A CRASH ---
[10:37:10 ERROR]: ------------------------------

Desktop (please complete the following information):

• Server type Paper
• Minecraft Version 1.12
• PowerRanks version 1.9.6 (1.9.7?)