Does anyone know how to fix this?
07.12 12:49:09 [Server] Server thread/INFO chengze ran the command: /skin-upload https://i.imgur.com/KS1MOAy.png
07.12 12:50:10 [Server] pool-3-thread-5/ERROR The Scheduler tried to run the task changeskin-A-186 owned by Plugin{id=changeskin, name=ChangeSkin, version=3.1-SNAPSHOT-4f0f54a, description=Change your Minecraft skin in-game, url=https://dev.bukkit.org/bukkit-plugins/changeskin/, source=./mods/ChangeSkinSponge (4).jar}, but an error occured.
07.12 12:50:10 [Server] INFO java.lang.IllegalArgumentException: Invalid UUID string:
07.12 12:50:10 [Server] INFO at java.util.UUID.fromString(UUID.java:194) ~[?:1.8.0_191]
07.12 12:50:10 [Server] INFO at com.github.games647.changeskin.core.model.UUIDTypeAdapter.parseId(UUIDTypeAdapter.java:17) ~[UUIDTypeAdapter.class:?]
07.12 12:50:10 [Server] INFO at com.github.games647.changeskin.core.shared.task.SharedSkinChanger.run(SharedSkinChanger.java:26) ~[SharedSkinChanger.class:?]
07.12 12:50:10 [Server] INFO at org.spongepowered.api.scheduler.Task$Builder.lambda$execute$0(Task.java:139) ~[Task$Builder.class:1.12.2-2838-7.1.7]
07.12 12:50:10 [Server] INFO at org.spongepowered.common.scheduler.SchedulerBase.lambda$startTask$0(SchedulerBase.java:197) ~[SchedulerBase.class:1.12.2-2838-7.1.7]
07.12 12:50:10 [Server] INFO at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_191]
07.12 12:50:10 [Server] INFO at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_191]
07.12 12:50:10 [Server] INFO at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_191]
07.12 12:50:10 [Server] INFO at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_191]
07.12 12:50:10 [Server] INFO at java.lang.Thread.run(Thread.java:748) [?:1.8.0_191]