Observed Behavior

During startup of Paper with GriefPrevention loaded, you will get this warning now in 1.21.7:
02.07 16:07:53 [Server] INFO [HorriblePlayerLoginEventHack] You have plugins listening to the PlayerLoginEvent, this will cause re-configuration APIs to be unavailable: [GriefPrevention]

More info about it here: https://forums.papermc.io/threads/1-21-7.1635/

Though I'd give you a heads up if you don't already know(which you probably do). It doesn't seem to be an urgent thing.

Expected Behavior

No warning during startup

Reproduction steps

1. Start Paper with GriefPrevention loaded and watch the log

Stack trace or error log

02.07 16:07:53 [Server] INFO [HorriblePlayerLoginEventHack] You have plugins listening to the PlayerLoginEvent, this will cause re-configuration APIs to be unavailable: [GriefPrevention]

Server version

02.07 16:14:39 [Server] INFO This server is running Paper version 1.21.7-15-main@0cadaef (2025-07-01T22:53:44Z) (Implementing API version 1.21.7-R0.1-SNAPSHOT)

GriefPrevention version

02.07 16:21:22 [Server] INFO GriefPrevention version 16.18.4

Configuration

.

Plugin list

Running without GriefPrevention

• I attempted running the server without GriefPrevention installed.
• The problem does not occur when GriefPrevention is removed from the server.

Running with only GriefPrevention

• I attempted running only GriefPrevention on the server.
• The issue still occurs when GriefPrevention is the only plugin running.

Running on a fresh, clean server installation

• I attempted testing for the issue on a new server.
• The issue still occurs on a new server.

Using unmodified client

• I attempted testing for the issue with the vanilla client.
• The issue still occurs when using the vanilla client.

We appreciate you taking the time to fill out a bug report!

• I searched for similar issues before submitting this bug report.

Fun, I guess they want people to use AsyncPlayerLoginEvent or something?

20:57]granny[SQID]
: basically that event is stupid and should be avoided on paper
[20:58]granny[SQID]
: https://forums.papermc.io/threads/1-21-7.1635/
[21:18]RoboMWM[SPGT]
: Is PlayerConnectionValidateLoginEvent also in spigot?
[21:19]QarthO: its not
[21:31]granny[SQID]
: this is one of those things where paper api starts diverging from spigot api :3
[21:32]RoboMWM[SPGT]
: guh
[21:32]granny[SQID]
: it's not really something spigot would be able to support easily - if they did, it'd be really hacky

Seems I removed the discussion label, but given this will eventually turn into some sort of work item, I'll leave it as an issue instead of transferring to discussion forum.

As far as I'm aware, we only use this for preventing login/logout spam and for the smartban feature. I guess this would be a good candidate for the modules stuff Jikoo was proposing earlier, and perhaps some method to autodetect if on spigot or paper and load in the appropriate module or something.