Hello, this error occurred on disabling the plugin.
I do not believe it has happened before.

[14:25:38] [Server thread/INFO]: [HyperConomy] Disabling HyperConomy v0.975.5
[14:25:39] [Craft Scheduler Thread - 20/WARN]: java.lang.NullPointerException
[14:25:39] [Craft Scheduler Thread - 20/WARN]: at regalowl.hyperconomy.util.History.getPercentChange(History.java:182)
[14:25:39] [Craft Scheduler Thread - 20/WARN]: at regalowl.hyperconomy_web.ShopPage.buildPage(ShopPage.java:80)
[14:25:39] [Craft Scheduler Thread - 20/WARN]: at regalowl.hyperconomy_web.ShopPage.access$200(ShopPage.java:24)
[14:25:39] [Craft Scheduler Thread - 20/WARN]: at regalowl.hyperconomy_web.ShopPage$1.run(ShopPage.java:50)
[14:25:39] [Craft Scheduler Thread - 20/WARN]: at org.bukkit.craftbukkit.v1_8_R1.scheduler.CraftTask.run(CraftTask.java:71)
[14:25:39] [Craft Scheduler Thread - 20/WARN]: at org.bukkit.craftbukkit.v1_8_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
[14:25:39] [Craft Scheduler Thread - 20/WARN]: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
[14:25:39] [Craft Scheduler Thread - 20/WARN]: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
[14:25:39] [Craft Scheduler Thread - 20/WARN]: at java.lang.Thread.run(Thread.java:745)
[14:25:39] [Craft Scheduler Thread - 19/WARN]: java.lang.NullPointerException
[14:25:39] [Craft Scheduler Thread - 19/WARN]: at regalowl.hyperconomy.util.History.getPercentChange(History.java:182)
[14:25:39] [Craft Scheduler Thread - 19/WARN]: at regalowl.hyperconomy_web.ShopPage.buildPage(ShopPage.java:79)
[14:25:39] [Craft Scheduler Thread - 19/WARN]: at regalowl.hyperconomy_web.ShopPage.access$200(ShopPage.java:24)
[14:25:39] [Craft Scheduler Thread - 19/WARN]: at regalowl.hyperconomy_web.ShopPage$1.run(ShopPage.java:50)
[14:25:39] [Craft Scheduler Thread - 19/WARN]: at org.bukkit.craftbukkit.v1_8_R1.scheduler.CraftTask.run(CraftTask.java:71)
[14:25:39] [Craft Scheduler Thread - 19/WARN]: at org.bukkit.craftbukkit.v1_8_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
[14:25:39] [Craft Scheduler Thread - 19/WARN]: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
[14:25:39] [Craft Scheduler Thread - 19/WARN]: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
[14:25:39] [Craft Scheduler Thread - 19/WARN]: at java.lang.Thread.run(Thread.java:745)
[14:25:39] [Craft Scheduler Thread - 18/WARN]: java.lang.NullPointerException
[14:25:39] [Craft Scheduler Thread - 18/WARN]: at regalowl.hyperconomy.util.History.getPercentChange(History.java:182)
[14:25:39] [Craft Scheduler Thread - 18/WARN]: at regalowl.hyperconomy_web.ShopPage.buildPage(ShopPage.java:79)
[14:25:39] [Craft Scheduler Thread - 18/WARN]: at regalowl.hyperconomy_web.ShopPage.access$200(ShopPage.java:24)
[14:25:39] [Craft Scheduler Thread - 18/WARN]: at regalowl.hyperconomy_web.ShopPage$1.run(ShopPage.java:50)
[14:25:39] [Craft Scheduler Thread - 18/WARN]: at org.bukkit.craftbukkit.v1_8_R1.scheduler.CraftTask.run(CraftTask.java:71)
[14:25:39] [Craft Scheduler Thread - 18/WARN]: at org.bukkit.craftbukkit.v1_8_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
[14:25:39] [Craft Scheduler Thread - 18/WARN]: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
[14:25:39] [Craft Scheduler Thread - 18/WARN]: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
[14:25:39] [Craft Scheduler Thread - 18/WARN]: at java.lang.Thread.run(Thread.java:745)
[14:25:39] [Craft Scheduler Thread - 17/WARN]: java.lang.NullPointerException
[14:25:39] [Craft Scheduler Thread - 17/WARN]: at regalowl.hyperconomy.util.History.getPercentChange(History.java:182)
[14:25:39] [Craft Scheduler Thread - 17/WARN]: at regalowl.hyperconomy_web.ShopPage.buildPage(ShopPage.java:79)
[14:25:39] [Craft Scheduler Thread - 17/WARN]: at regalowl.hyperconomy_web.ShopPage.access$200(ShopPage.java:24)
[14:25:39] [Craft Scheduler Thread - 17/WARN]: at regalowl.hyperconomy_web.ShopPage$1.run(ShopPage.java:50)
[14:25:39] [Craft Scheduler Thread - 17/WARN]: at org.bukkit.craftbukkit.v1_8_R1.scheduler.CraftTask.run(CraftTask.java:71)
[14:25:39] [Craft Scheduler Thread - 17/WARN]: at org.bukkit.craftbukkit.v1_8_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
[14:25:39] [Craft Scheduler Thread - 17/WARN]: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
[14:25:39] [Craft Scheduler Thread - 17/WARN]: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
[14:25:39] [Craft Scheduler Thread - 17/WARN]: at java.lang.Thread.run(Thread.java:745)
[14:25:39] [Craft Scheduler Thread - 16/WARN]: java.lang.NullPointerException
[14:25:39] [Craft Scheduler Thread - 16/WARN]: at regalowl.hyperconomy.util.History.getPercentChange(History.java:182)
[14:25:39] [Craft Scheduler Thread - 16/WARN]: at regalowl.hyperconomy_web.ShopPage.buildPage(ShopPage.java:79)
[14:25:39] [Craft Scheduler Thread - 16/WARN]: at regalowl.hyperconomy_web.ShopPage.access$200(ShopPage.java:24)
[14:25:39] [Craft Scheduler Thread - 16/WARN]: at regalowl.hyperconomy_web.ShopPage$1.run(ShopPage.java:50)
[14:25:39] [Craft Scheduler Thread - 16/WARN]: at org.bukkit.craftbukkit.v1_8_R1.scheduler.CraftTask.run(CraftTask.java:71)
[14:25:39] [Craft Scheduler Thread - 16/WARN]: at org.bukkit.craftbukkit.v1_8_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
[14:25:39] [Craft Scheduler Thread - 16/WARN]: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
[14:25:39] [Craft Scheduler Thread - 16/WARN]: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
[14:25:39] [Craft Scheduler Thread - 16/WARN]: at java.lang.Thread.run(Thread.java:745)
[14:25:40] [Craft Scheduler Thread - 12/WARN]: java.lang.NullPointerException
[14:25:40] [Craft Scheduler Thread - 12/WARN]: at regalowl.hyperconomy.util.History.getPercentChange(History.java:182)
[14:25:40] [Craft Scheduler Thread - 12/WARN]: at regalowl.hyperconomy_web.ShopPage.buildPage(ShopPage.java:79)
[14:25:40] [Craft Scheduler Thread - 12/WARN]: at regalowl.hyperconomy_web.ShopPage.access$200(ShopPage.java:24)
[14:25:40] [Craft Scheduler Thread - 12/WARN]: at regalowl.hyperconomy_web.ShopPage$1.run(ShopPage.java:50)
[14:25:40] [Craft Scheduler Thread - 12/WARN]: at org.bukkit.craftbukkit.v1_8_R1.scheduler.CraftTask.run(CraftTask.java:71)
[14:25:40] [Craft Scheduler Thread - 12/WARN]: at org.bukkit.craftbukkit.v1_8_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53)
[14:25:40] [Craft Scheduler Thread - 12/WARN]: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
[14:25:40] [Craft Scheduler Thread - 12/WARN]: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
[14:25:40] [Craft Scheduler Thread - 12/WARN]: at java.lang.Thread.run(Thread.java:745)