title: Can anyone explain possible causes of these errors in the server console (for Minecraft)?
body: <p>Reposting this from a Reddit post I made as I've had no response and still have no idea. Would really appreciate some guidance.</p>
  <h2>Summary: My test server has randomly decided to not load particular function files of my datapack that had previously worked before. The server console is saying it is &quot;Not Supported.&quot;</h2>
  <p>It's likely an issue with the paper.jar file, it's put a huge block on my pack development D:
  The server console is throwing the same/similar errors when trying to load a handful of function files. An example is below. I cannot share the datapack atm (private and there are 8 individual function files affected, although built using the same method), but the different files all vary in command usage, some even using execute and some not. Most/all use the trigger command in some way and commenting those commands out in some doesn't fix the issue for every function.
  <strong>Edit: I have very little understanding of Java so simpler explanations/extra pointers would be very appreciated</strong></p>
  <p>Other Details:</p>
  <ul>
  <li>Function Permission Level is set to 3 in the server.properties file (default is usually 2)</li>
  <li>Everything worked fine when I last worked on this, so there must be some update that has changed something I am oblivious to.</li>
  <li>The (Test) server is running on 1.17.1 Paper</li>
  <li>I've had a look at similar issues, and had little luck. The only reasonable suggestion was the permission level of functions</li>
  <li>Some functions are set to execute via an advancement, and then target the player using the @s selector which worked like a treat in the past. The datapack is to support multiple players</li>
  </ul>
  <pre><code>27.08 16:26:02 [Server] INFO java.util.concurrent.CompletionException: java.lang.UnsupportedOperationException: Not supported yet.
  27.08 16:26:02 [Server] INFO at java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:314) ~[?:?]
  27.08 16:26:02 [Server] INFO at java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:319) ~[?:?]
  27.08 16:26:02 [Server] INFO at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1766) ~[?:?]
  27.08 16:26:02 [Server] INFO at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130) ~[?:?]
  27.08 16:26:02 [Server] INFO at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630) ~[?:?]
  27.08 16:26:02 [Server] INFO at java.lang.Thread.run(Thread.java:831) [?:?]
  27.08 16:26:02 [Server] INFO Caused by: java.lang.UnsupportedOperationException: Not supported yet.
  27.08 16:26:02 [Server] INFO at net.minecraft.commands.ICommandListener$1.getBukkitSender(ICommandListener.java:30) ~[patched_1.17.1.jar:git-Paper-&quot;08f746f&quot;]
  27.08 16:26:02 [Server] INFO at net.minecraft.commands.CommandListenerWrapper.getBukkitSender(CommandListenerWrapper.java:322) ~[patched_1.17.1.jar:git-Paper-&quot;08f746f&quot;]
  27.08 16:26:02 [Server] INFO at net.minecraft.commands.CommandDispatcher.lambda$new$0(CommandDispatcher.java:210) ~[patched_1.17.1.jar:git-Paper-&quot;08f746f&quot;]
  27.08 16:26:02 [Server] INFO at com.mojang.brigadier.tree.CommandNode.canUse(CommandNode.java:78) ~[patched_1.17.1.jar:git-Paper-&quot;08f746f&quot;]
  27.08 16:26:02 [Server] INFO at com.mojang.brigadier.CommandDispatcher.parseNodes(CommandDispatcher.java:358) ~[patched_1.17.1.jar:git-Paper-&quot;08f746f&quot;]
  27.08 16:26:02 [Server] INFO at com.mojang.brigadier.CommandDispatcher.parseNodes(CommandDispatcher.java:388) ~[patched_1.17.1.jar:git-Paper-&quot;08f746f&quot;]
  27.08 16:26:02 [Server] INFO at com.mojang.brigadier.CommandDispatcher.parseNodes(CommandDispatcher.java:388) ~[patched_1.17.1.jar:git-Paper-&quot;08f746f&quot;]
  27.08 16:26:02 [Server] INFO at com.mojang.brigadier.CommandDispatcher.parseNodes(CommandDispatcher.java:392) ~[patched_1.17.1.jar:git-Paper-&quot;08f746f&quot;]
  27.08 16:26:02 [Server] INFO at com.mojang.brigadier.CommandDispatcher.parseNodes(CommandDispatcher.java:392) ~[patched_1.17.1.jar:git-Paper-&quot;08f746f&quot;]
  27.08 16:26:02 [Server] INFO at com.mojang.brigadier.CommandDispatcher.parse(CommandDispatcher.java:348) ~[patched_1.17.1.jar:git-Paper-&quot;08f746f&quot;]
  27.08 16:26:02 [Server] INFO at net.minecraft.commands.CustomFunction.a(CustomFunction.java:61) ~[patched_1.17.1.jar:git-Paper-&quot;08f746f&quot;]
  27.08 16:26:02 [Server] INFO at net.minecraft.server.CustomFunctionManager.lambda$reload$3(CustomFunctionManager.java:86) ~[patched_1.17.1.jar:git-Paper-&quot;08f746f&quot;]
  27.08 16:26:02 [Server] INFO at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1764) ~[?:?]
  27.08 16:26:02 [Server] INFO ... 3 more```
  </code></pre>