Bukkit

What steps will reproduce the problem?
1. Put anything inside the "races_command_after_change:" inside the config.yml
2. Start the server
3. Errors in log

What is the expected output? What do you see instead?

10:32:33 AM [SEVERE] Could not pass event AfterRaceSelectedEvent to RacesAndClasses v1.2.1
10:32:33 AM org.bukkit.event.EventException
10:32:33 AM     at org.bukkit.plugin.EventExecutor$1.execute(EventExecutor.java:46) ~[patched_1.10.2.jar:git-Paper-899]
10:32:33 AM     at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:78) ~[patched_1.10.2.jar:git-Paper-899]
10:32:33 AM     at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[patched_1.10.2.jar:git-Paper-899]
10:32:33 AM     at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:517) [patched_1.10.2.jar:git-Paper-899]
10:32:33 AM     at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:502) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at de.tobiyas.racesandclasses.RacesAndClasses.fireEventToBukkit(RacesAndClasses.java:543) [RacesAndClasses.jar:?]
10:32:34 AM     at de.tobiyas.racesandclasses.datacontainer.traitholdercontainer.AbstractHolderManager.addPlayerToHolder(AbstractHolderManager.java:223) [RacesAndClasses.jar:?]
10:32:34 AM     at de.tobiyas.racesandclasses.datacontainer.traitholdercontainer.race.RaceManager.addPlayerToHolder(RaceManager.java:121) [RacesAndClasses.jar:?]
10:32:34 AM     at de.tobiyas.racesandclasses.listeners.generallisteners.Listener_Player.onPlayerJoin(Listener_Player.java:100) [RacesAndClasses.jar:?]
10:32:34 AM     at com.destroystokyo.paper.event.executor.asm.generated.GeneratedEventExecutor286.execute(Unknown Source) [?:?]
10:32:34 AM     at org.bukkit.plugin.EventExecutor$1.execute(EventExecutor.java:44) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at co.aikar.timings.TimedEventExecutor.execute(TimedEventExecutor.java:78) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:517) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:502) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at net.minecraft.server.v1_10_R1.PlayerList.onPlayerJoin(PlayerList.java:357) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at net.minecraft.server.v1_10_R1.PlayerList.a(PlayerList.java:177) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at net.minecraft.server.v1_10_R1.LoginListener.b(LoginListener.java:144) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at net.minecraft.server.v1_10_R1.LoginListener.E_(LoginListener.java:54) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at net.minecraft.server.v1_10_R1.NetworkManager.a(NetworkManager.java:233) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at net.minecraft.server.v1_10_R1.ServerConnection.c(ServerConnection.java:152) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at net.minecraft.server.v1_10_R1.MinecraftServer.D(MinecraftServer.java:897) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at net.minecraft.server.v1_10_R1.DedicatedServer.D(DedicatedServer.java:404) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at net.minecraft.server.v1_10_R1.MinecraftServer.C(MinecraftServer.java:734) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at net.minecraft.server.v1_10_R1.MinecraftServer.run(MinecraftServer.java:633) [patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     at java.lang.Thread.run(Unknown Source) [?:1.8.0_101]
10:32:34 AM Caused by: java.lang.NullPointerException
10:32:34 AM     at java.lang.String.replace(Unknown Source) ~[?:1.8.0_101]
10:32:34 AM     at de.tobiyas.racesandclasses.listeners.racechangelistener.RaceChangeSelectionListener.sendCommandAfterSelect(RaceChangeSelectionListener.java:187) ~[?:?]
10:32:34 AM     at com.destroystokyo.paper.event.executor.asm.generated.GeneratedEventExecutor253.execute(Unknown Source) ~[?:?]
10:32:34 AM     at org.bukkit.plugin.EventExecutor$1.execute(EventExecutor.java:44) ~[patched_1.10.2.jar:git-Paper-899]
10:32:34 AM     ... 25 more

What version of RacesAndClasses are you using?
RacesAndClasses v1.2.1

What version of Bukkit / what distribution are you using (Craftbukkit, Spigot, Cauldron, ...)?
1.10.2.jar:git-Paper-899

Do you have an error log of what happened?
Yes

Please provide any additional information below.

The goal was to have the player assigned to a group after selecting a race, example:"%CONSOLE%pex user %PLAYER% group set %RACE%", but regardless what I put inside this string, it throws an error.

I have tried both Paper Spigot and normal Spigot, same result.