Error when interacting with anything on 1.8.8 backend

[Defective4]

Describe the bug
When using protocolize on waterfall 1.20 and joining a 1.8.8 backend
an error occurs and kicks the client:

[08:46:37 WARN]: [/10.0.0.1:41818|Defective4] -> UpstreamBridge - A decoder exception has been thrown:
net.md_5.bungee.protocol.FastDecoderException: Error decoding packet class GeneratedBlockPlacementWrapper with contents:
         +-------------------------------------------------+
         |  0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f |
+--------+-------------------------------------------------+----------------+
|00000000| 08 ff ff 76 80 cb ff fe e9 01 00 00 00 00 00 00 |...v............|
|00000010| 0f 10 0b                                        |...             |
+--------+-------------------------------------------------+----------------+
Caused by: net.md_5.bungee.protocol.BadPacketException: Packet GAME:TO_SERVER/8 (GeneratedBlockPlacementWrapper) larger than expected, extra bytes: 1
[08:46:37 INFO]: [Defective4] disconnected with: FastDecoderException : Error decoding packet class GeneratedBlockPlacementWrapper with contents:
         +-------------------------------------------------+
         |  0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f |
+--------+-------------------------------------------------+----------------+
|00000000| 08 ff ff 76 80 cb ff fe e9 01 00 00 00 00 00 00 |...v............|
|00000010| 0f 10 0b                                        |...             |
+--------+-------------------------------------------------+----------------+

This issue persists no matter the client's version (I'm using latest ViaVersion)
The issue doesn't happen on versions >= 1.12, I can't test if the same applies for < 1.12

To Reproduce
Steps to reproduce the behavior:

1. Set up waterfall 1.20 with ViaVersion and Protocolize and a 1.8.8 (paper) backend
2. Join the server
3. Right-click anything
4. Get kicked with an error

Expected behavior
Players should be able to play as normal

Proxy environment
Proxy: waterfall-1.20-536
Protocolize: latest at the time
ViaVersion: 4.7.0

Minecraft versions used
Minecraft versions: ALL tested, none of them is able to successfully play on the server
Backend versions:

• 1.8.8 - ❌
• 1.12.2 - 1.20.x - ✅

[Defective4]

Update
The issue seems to persist even without ViaVersion installed on the proxy, but only when the 1.8.8 client connects.
So for example C (1.16.5) -> S (1.8.8) with ViaVersion installed on the backend IS possible, but
C (1.8.8) -> S (1.8.8) in the same environment IS NOT.

[jehendeoff]

Hi, I think you need the legacy addon for protocolizer if you want 1.8 support, I'm doing a similar setup to you (waterfall with the legacy addon, to pandaspigot (a fork of paper, not spigot) with viaversion there) and I can connect with 1.8.9 without ant error

[Defective4]

Hi @jehendeoff!
Actually I forgot to mention but I have the protocolize-legacy module installed

[Exceptionflug]

Sorry for the late response. At first I don't recommend installing ViaVersion on the proxy server. Nevertheless this issue still is present so I assume it has to do with the packet decoding. Are mods in use? This issue would definetely occur everywhere else if it was a general decoding issues for all Minecraft client versions. The Backend Server version in this case is irrellevant since the error occurs during decoding of the player packets. Please be sure to run the latest version of the proxy and Protocolize.

[Exceptionflug]

Any update on this?

[Defective4]

Oh, yeah, sorry for not responding!
There are absolutely no mods. The issue happens even on vanilla 1.8.8 server and without any other plugins installed on the proxy.

[Exceptionflug]

Does this issue still occur with the latest version of Waterfall and Protocolize?

[MathsAnalysis]

I have viaversion on bukkit I can't put it, I can't put it in both as the same dev of viaversion says also I need it on bukkit how can I solve ?

[Exceptionflug]

I have viaversion on bukkit I can't put it, I can't put it in both as the same dev of viaversion says also I need it on bukkit how can I solve ?

I don't quite understand what you mean, but you can't run ViaVersion on bukkit and on the proxy, that's right. You also don't have to run ViaVersion on the proxy since I cannot recommend doing so.

[Defective4]

Does this issue still occur with the latest version of Waterfall and Protocolize?

I'm going to re-check it, thanks