RejectedExecutionException errors in server console

Hi there,
I've been trying to pregen/gen some chunks on my server but I get these errors when generating lods. I can't find anything online about it, so I came here for help

Error:

>....Exception in thread "DH-PriorityTaskPicker Thread[10185]" java.util.concurrent.RejectedExecutionException: Task com.seibel.distanthorizons.core.util.threading.PriorityTaskPicker$TrackedRunnable@3b44dff1 rejected from com.seibel.distanthorizons.core.util.threading.RateLimitedThreadPoolExecutor@a80e14a[Running, pool size = 4, active threads = 4, queued tasks = 4, completed tasks = 230191]
        at java.base/java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:2081)
        at java.base/java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:841)
        at java.base/java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1376)
        at TRANSFORMER/distanthorizons@2.3.2-b/com.seibel.distanthorizons.core.util.threading.PriorityTaskPicker.tryStartNextTask(PriorityTaskPicker.java:78)
        at TRANSFORMER/distanthorizons@2.3.2-b/com.seibel.distanthorizons.core.util.threading.PriorityTaskPicker.access$200(PriorityTaskPicker.java:17)
        at TRANSFORMER/distanthorizons@2.3.2-b/com.seibel.distanthorizons.core.util.threading.PriorityTaskPicker$TrackedRunnable.run(PriorityTaskPicker.java:217)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
        at java.base/java.lang.Thread.run(Thread.java:1583)

>....Exception in thread "DH-PriorityTaskPicker Thread[10185]" java.util.concurrent.RejectedExecutionException: Task com.seibel.distanthorizons.core.util.threading.PriorityTaskPicker$TrackedRunnable@3b44dff1 rejected from com.seibel.distanthorizons.core.util.threading.RateLimitedThreadPoolExecutor@a80e14a[Running, pool size = 4, active threads = 4, queued tasks = 4, completed tasks = 230191]
        at java.base/java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:2081)
        at java.base/java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:841)
        at java.base/java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1376)
        at TRANSFORMER/distanthorizons@2.3.2-b/com.seibel.distanthorizons.core.util.threading.PriorityTaskPicker.tryStartNextTask(PriorityTaskPicker.java:78)
        at TRANSFORMER/distanthorizons@2.3.2-b/com.seibel.distanthorizons.core.util.threading.PriorityTaskPicker.access$200(PriorityTaskPicker.java:17)
        at TRANSFORMER/distanthorizons@2.3.2-b/com.seibel.distanthorizons.core.util.threading.PriorityTaskPicker$TrackedRunnable.run(PriorityTaskPicker.java:217)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
        at java.base/java.lang.Thread.run(Thread.java:1583)

Full Log: https://mcpaste.io/8fb97081d1ea3176
Modlist: https://mcpaste.io/f5abe649e2e4525c
Mutiplayer - Hosted on pebblehost.

Thanks for the help and the awesome mod!

MCPaste.io

A easy to use Paste site for Minecraft Server logs.

MCPaste.io

A easy to use Paste site for Minecraft Server logs.

Solution

The nightly version works without errors! It also seems like lod generation is fully working (albeit, still quite slow).

Jump to solution

beanoOP•4/12/25, 7:15 AM

Oops, forgot to mention I'm on Minecraft 1.21.1, Neoforge 21.1.141, and DH 2.3.2-b (but I had the same issue on older DH versions)

beanoOP•4/12/25, 7:18 AM

(I have the same issue with chunky, dh pregen, and a player generating chunks)

Jckf•4/12/25, 9:21 AM

Is your server running under some sort of web hosting panel?

JJckf Is your server running under some sort of web hosting panel?

beanoOP•4/12/25, 10:09 AM

It's on pebblehost, so its running on their game hosting panel (probably modified pterodactyl).

Jckf•4/12/25, 11:49 AM

Hm. Please post the full /logs

YAGPDB.xyz•4/12/25, 11:49 AM

You should send your file to provide additional useful information.

Logs are usually located in the directory.
On Windows:
On Linux:
On Mac:

Please upload the file to mclo.gs instead of sending the raw file. This makes reading the contents of the file a lot easier and improves the chances of you getting the help needed.
After uploading the file, click on and send the link.

beanoOP•4/12/25, 9:57 PM

https://mclo.gs/oIBWUZS

mclo.gs

NeoForge 1.21.1 Server Log [#oIBWUZS]

1101 lines | 117 errors

Jckf•4/12/25, 10:20 PM

This log does not have that error

JJckf This log does not have that error

beanoOP•4/12/25, 10:53 PM

Interestingly, the error doesn't show in latest.log. Only in the server panel. I can send you the logs from the panel, but it will probably be cut off at the start.

Jckf•4/12/25, 10:55 PM

What I'm looking for is any error message preceeding this one, to see if the error you posted is a result of something else going wrong first

JJckf What I'm looking for is any error message preceeding this one, to see if the err...

beanoOP•4/12/25, 10:58 PM

Heres the most I can get out of the console
https://mclo.gs/BB4FzoX

mclo.gs

Fabric Server Log [#BB4FzoX]

660 lines

Jckf•4/12/25, 10:58 PM

Yeah that doesn't help, sadly, since the very first things is the error you posted

JJckf Yeah that doesn't help, sadly, since the very first things is the error you post...

beanoOP•4/12/25, 11:02 PM

This one should be better, but pebblehost still cuts off the start
https://mclo.gs/WrPNJZN

mclo.gs

Fabric 1.21.1 Server Log [#WrPNJZN]

434 lines | 114 errors

Jckf•4/12/25, 11:14 PM

Hm, nothing new to go on. It looks to me like this tasks executor is just saturated and cannot accept all the tasks it is being handed. The errors all state that it has 4 threads and 4 currently queued tasks, with a varying number of already completed tasks.

Do the errors eventually stop, or is DH just constantly spamming this?

JJckf Hm, nothing new to go on. It looks to me like this tasks executor is just satura...

beanoOP•4/12/25, 11:16 PM

I've been pregenerating (using dh pregen) overnight and still get it errors, roughly 2 per second.

Jckf•4/12/25, 11:17 PM

Any apparent issues when in-game, or does everything still work?

JJckf Any apparent issues when in-game, or does everything still work?

beanoOP•4/12/25, 11:19 PM

The only issue I can see is extremely slow lod generation (minutes a chunk). Although, that could just be related to hardware.

Jckf•4/12/25, 11:20 PM

That's pretty severe. An RPi 5 can do about 8 LODs per second

Jckf•4/12/25, 11:20 PM

if the chunks are pre-generated

Jckf•4/12/25, 11:21 PM

At least with the plugin, but the mod shouldn't be very far off in performance in ither direction

JJckf That's pretty severe. An RPi 5 can do about 8 LODs per second

beanoOP•4/12/25, 11:23 PM

hmm, annoying. The TPS stays at 20 with no lag when playing, even when lods are generating, so that hints more at threading issues than performance

beanoOP•4/12/25, 11:23 PM

I could try with the nightly if that helps

Jckf•4/12/25, 11:24 PM

Yeah, that's why my initial question was whether it's running under some sort of web panel - because it might be imposing weird restrictions

JJckf Yeah, that's why my initial question was whether it's running under some sort of...

beanoOP•4/12/25, 11:25 PM

I'll try the nightly just in case. Do you think I should contact pebblehost support, maybe its a known issue with their panel?

Jckf•4/12/25, 11:27 PM

Let's try @James Seibel GMT-5 first. He's on vacation, but maybe he's got a spare moment

beanoOP•4/12/25, 11:28 PM

sounds good!

Solution

JJckf Let's try @James Seibel GMT-5 first. He's on vacation, but maybe he's got a spar...

beano•4/12/25, 11:31 PM

The nightly version works without errors! It also seems like lod generation is fully working (albeit, still quite slow).

Jckf•4/12/25, 11:32 PM

Oh, nice! I had seen this error once before, but not any specific fix related to it

Jckf•4/12/25, 11:32 PM

But I guess it must have been known then

Jckf•4/12/25, 11:32 PM

Great!

beanoOP•4/12/25, 11:33 PM

Thanks for the help!