java.lang.ClassCastException: class org.enginehub.piston.converter.SuccessfulConversion cannot be cast to class org.enginehub.piston.converter.FailedConversion

Server Implementation

Paper

Server Version

1.20.4

Describe the bug

When I connect to my server, I sometimes get this error in log:

[00:00:51] [AsyncNotifyKeyedQueue - 1/ERROR]: An unexpected error while handling a FastAsyncWorldEdit command
java.lang.ClassCastException: class org.enginehub.piston.converter.SuccessfulConversion cannot be cast to class org.enginehub.piston.converter.FailedConversion (org.enginehub.piston.converter.SuccessfulConversion and org.enginehub.piston.converter.FailedConversion are in unnamed module of loader 'FastAsyncWorldEdit-Bukkit-2.13.1-SNAPSHOT-1116.jar' @4824c4d6)
	at org.enginehub.piston.impl.CommandParser.conversionFailedException(CommandParser.java:190) ~[FastAsyncWorldEdit-Bukkit-2.13.1-SNAPSHOT-1116.jar:?]
	at org.enginehub.piston.impl.CommandParser.parse(CommandParser.java:346) ~[FastAsyncWorldEdit-Bukkit-2.13.1-SNAPSHOT-1116.jar:?]
	at org.enginehub.piston.impl.CommandManagerImpl.parse(CommandManagerImpl.java:240) ~[FastAsyncWorldEdit-Bukkit-2.13.1-SNAPSHOT-1116.jar:?]
	at org.enginehub.piston.CommandManager.execute(CommandManager.java:154) ~[FastAsyncWorldEdit-Bukkit-2.13.1-SNAPSHOT-1116.jar:?]
	at com.sk89q.worldedit.extension.platform.PlatformCommandManager.lambda$handleCommandOnCurrentThread$16(PlatformCommandManager.java:712) ~[FastAsyncWorldEdit-Bukkit-2.13.1-SNAPSHOT-1116.jar:?]
	at com.sk89q.worldedit.extension.platform.PlatformCommandManager.handleCommandTask(PlatformCommandManager.java:733) ~[FastAsyncWorldEdit-Bukkit-2.13.1-SNAPSHOT-1116.jar:?]
	at com.sk89q.worldedit.extension.platform.PlatformCommandManager.handleCommandOnCurrentThread(PlatformCommandManager.java:714) ~[FastAsyncWorldEdit-Bukkit-2.13.1-SNAPSHOT-1116.jar:?]
	at com.sk89q.worldedit.extension.platform.PlatformCommandManager.lambda$handleCommand$14(PlatformCommandManager.java:685) ~[FastAsyncWorldEdit-Bukkit-2.13.1-SNAPSHOT-1116.jar:?]
	at com.sk89q.worldedit.extension.platform.AbstractNonPlayerActor.lambda$runAction$1(AbstractNonPlayerActor.java:104) ~[FastAsyncWorldEdit-Bukkit-2.13.1-SNAPSHOT-1116.jar:?]
	at com.fastasyncworldedit.core.util.task.AsyncNotifyKeyedQueue.lambda$run$0(AsyncNotifyKeyedQueue.java:48) ~[FastAsyncWorldEdit-Bukkit-2.13.1-SNAPSHOT-1116.jar:?]
	at com.fastasyncworldedit.core.util.task.AsyncNotifyKeyedQueue.lambda$call$1(AsyncNotifyKeyedQueue.java:58) ~[FastAsyncWorldEdit-Bukkit-2.13.1-SNAPSHOT-1116.jar:?]
	at java.util.concurrent.FutureTask.run(FutureTask.java:317) ~[?:?]
	at com.fastasyncworldedit.core.util.task.KeyQueuedExecutorService$KeyRunner.lambda$run$0(KeyQueuedExecutorService.java:150) ~[FastAsyncWorldEdit-Bukkit-2.13.1-SNAPSHOT-1116.jar:?]
	at java.util.concurrent.ForkJoinTask$RunnableExecuteAction.exec(ForkJoinTask.java:1423) ~[?:?]
	at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:387) ~[?:?]
	at java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1310) ~[?:?]
	at java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1841) ~[?:?]
	at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1806) ~[?:?]
	at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:188) ~[?:?]
[00:00:51] [AsyncNotifyKeyedQueue - 1/INFO]: &cPlease report this error: [See console]
[00:00:51] [AsyncNotifyKeyedQueue - 1/INFO]: java.lang.ClassCastException: class org.enginehub.piston.converter.SuccessfulConversion cannot be cast to class org.enginehub.piston.converter.FailedConversion (org.enginehub.piston.converter.SuccessfulConversion and org.enginehub.piston.converter.FailedConversion are in unnamed module of loader 'FastAsyncWorldEdit-Bukkit-2.13.1-SNAPSHOT-1116.jar' @4824c4d6)

To Reproduce

1. Connect to a server having FAWE installed

Expected behaviour

The error should not occour

Screenshots / Videos

No response

Error log (if applicable)

No response

Fawe Debugpaste

https://athion.net/ISPaster/paste/view/dbc749cbc72e46fd81bdf29f0732ce1b

Fawe Version

2.13.1-SNAPSHOT-1116;d955ea6

Checklist

• I have included a Fawe debugpaste.
• I am using the newest build from https://ci.athion.net/job/FastAsyncWorldEdit/ and the issue still persists.

Anything else?

No response

Start with org.enginehub.piston.impl.CommandParser.java at lines 190 and 346, then trace the call from CommandManagerImpl.parse at line 240. Reproduce the connection-triggered FastAsyncWorldEdit command path and determine which conversion result reaches conversionFailedException; done means the reported ClassCastException no longer appears in the server log.