Crash with FeatherBoard on Paper 1.21.8 build 60 – ProtocolLib fails decoding scoreboard packet

[Astroolean]

Using ProtocolLib with FeatherBoard on Paper 1.21.8 build 60 causes a crash when sending scoreboard packets.

Environment:

• Server: Paper 1.21.8 build 60 (29c8822)
• Plugin: FeatherBoard (latest)
• ProtocolLib: Latest available build
• Java: 17

Error (shortened):
Caused by: java.lang.IllegalStateException: Unable to invoke method public abstract java.lang.Object net.minecraft.network.codec.StreamDecoder.decode(java.lang.Object)
Caused by: io.netty.handler.codec.DecoderException: Not enough bytes in buffer, expected 4, but got 0
at net.minecraft.network.Utf8String.read
at net.minecraft.network.protocol.game.ClientboundSetObjectivePacket.
at com.comphenix.protocol.wrappers.WrappedStreamCodec.decode(WrappedStreamCodec.java:35)

Steps to reproduce:

1. Run Paper 1.21.8 build 60 with ProtocolLib and FeatherBoard installed.
2. Join the server.
3. FeatherBoard attempts to send scoreboard objectives.
4. ProtocolLib throws the above exception and FeatherBoard fails.

Expected:
Scoreboard packets should decode without errors.

Actual:
ProtocolLib fails to decode ClientboundSetObjectivePacket, throwing an IllegalStateException and crashing dependent plugins.

Notes:
This looks like a packet structure change in 1.21.8 that ProtocolLib hasn’t been updated for yet.