Connection lost due to custom items

[arsn98]

The server is running on 1.5.2, with self-written plugins. The server has a menu (in the form of a chest inventory), an "Information" tab, inside "Custom items" and crafting of these items should be described inside it.

When I go to this tab, Via Proxy throws me out of the server with the message "Connection lost"

debug.log

[RaphiMC]

This seems to be caused by your server/plugin sending invalid item data. Can you check if a vanilla 1.5.2 client can handle those items. To me it appears as if a vanilla 1.5.2 client would also crash

[arsn98]

Ванильная игра, голый майнкрафт

[RaphiMC]

I need a way to reproduce this issue if you want this to get fixed. Please provide steps on how I can reproduce the issue (Can be in the form of providing a server address and instructions how to get to that screen or sending me the plugin and instructions on how to set it up).