Describe the bug

when joining with a 1.20.5 client i get disconnected immediately (clients from 1.20 to 1.20.4 can connect normally)

To Reproduce

1. setup the server with the infos given
2. connect to the server with 1.20.5
3. see the error message

Expected behavior

join the server without a error message

Operating System

client: windows, server: linux

Server Software

paper 1.20.4 #496

Server Version

Not Listed

Proxy Type

Velocity

Plugin List

antipopup 8.1,
viaversion 4.10.2,
viabackwards 4.10.2

Server logs

no logs, only "Player lost connection: Disconnected"

Please confirm without antipopup.
(is it installed on the proxy? if so remove it from there and retry)

okay, apparently antipopup was installed on the proxy AND the backend,
dont really know how that happenend

thanks for your help!