Hi. I modify your plugin to get stacktrace and hope you will fix that NPE in next releases:

[Server thread/ERROR] [org.gestern.gringotts.Gringotts/]: [Gringotts] Encountered an error parsing currency. Please check your Gringotts configuration.
java.lang.NullPointerException
at org.gestern.gringotts.Configuration.unitName(Configuration.java:272)
at org.gestern.gringotts.Configuration.parseCurrency(Configuration.java:184)
at org.gestern.gringotts.Configuration.readConfig(Configuration.java:117)
at org.gestern.gringotts.Gringotts.reloadConfig(Gringotts.java:178)
at org.gestern.gringotts.Gringotts.onEnable(Gringotts.java:66)
at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:316)
at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:368)
at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:410)
at org.bukkit.craftbukkit.v1_7_R4.CraftServer.loadPlugin(CraftServer.java:415)
at org.bukkit.craftbukkit.v1_7_R4.CraftServer.enablePlugins(CraftServer.java:349)
at net.minecraft.world.storage.SaveHandler.initBukkitData(SaveHandler.java:462)
at net.minecraft.world.storage.SaveHandler.func_75757_d(SaveHandler.java:137)
at net.minecraft.world.World.(World.java:360)
at net.minecraft.world.WorldServer.(WorldServer.java:158)
at net.minecraft.server.MinecraftServer.func_71247_a(MinecraftServer.java:367)
at net.minecraft.server.dedicated.DedicatedServer.func_71197_b(DedicatedServer.java:336)
at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:631)
at java.lang.Thread.run(Thread.java:745)

What was the issue before you modified the plugin?

Plugin just don't load on startup. If i fill unit-name section in config manually, all works fine. You should add nullcheck to Configuration.unitName method.

Is this still an issue? In that case, please paste your complete Gringotts config in code format.

Assumed obsolete, closing.