Error when joining HUB

[Zilacon]

Hello I am getting this error when i try to join the HUB from my new modpack. I built the HUB when using other modpacks so not sure why this is happening.

http://i.imgur.com/CmybBBG.png

[Poweruser]

The error in the screenshot is happening on the server, which means, that one (or more) of the new mods in the pack is sending a packet to the server, which does not have the expected length.
The server is expecting 9 bytes, the client is sending 10.
Edit: It's the other way around - client expecting a different packet than the server sends

My guess is, that one (or more) of the mods is for a different minecraft version.

[Zilacon]

Everything on the modpack is for 1.7.10. Unless you can find otherwise?
I have no issues launching the modpack or joining the modpack server.
http://www.technicpack.net/modpack/apocalyptic-adventures.801085

[Poweruser]

Did a quick local test with your modpack. Joining and playing was at first no problem, until i drank a potion (default 8min night vision), where I got kicked with the same error and was unable to rejoin.
I cleared the potion effect by joining with the default client and drinking a bucket of milk, then I could continue to play.
This happens with active beacons as well. So basically anytime there's an effect on the player.

[Zilacon]

And there's beacons in the hub for speed buffs... Is there anyway to fix this?
Or do i have to rip out all of the beacons out of the hub?

[Poweruser]

Now that i can reproduce it, I'll see what's wrong there and what can be done about it

[Zilacon]

Ok, thanks a lot!

[Poweruser]

Correction: The internal exception is happening on the client, and it expects a different packet content length, than the one the server is sending. The specific packet class is PacketPlayOutEntityEffect
The mod that is causing this, is 1.7.10_AM2-1.4.0.009.jar. Without it the client stays connected. I don't know what excatly the mod does to cause this, and I dont really care.

There's also another very similiar protocol misunderstanding:
Internal Exception: io.netty.handler.codec.DecoderException: java.lang.IndexOutOfBoundsException: readerIndex(5) + length(4) exceeds writerIndex(6): UnpooledHeapByteBuf(ridx: 5, widx: 6, cap: 6)
It happens more randomly, once while flying, once while just standing around.

[Zilacon]

So take this up with the developer for Ars Magica 2?

[Poweruser]

Yes, and you apparently already do.

[Zilacon]

Yup, hopefully it can be fixed.
Thanks for helping pinpoint the problem.