[1.20.1] ItemsAdder error

[sj-hub9796]

Basic questions:

• [X] I am actually using ketting, and not any other software (e.g. magma)
• [X] I am using the latest Ketting version at the time of writing for the Minecraft version, that I am using
• [ ] I have provided full server logs and not a crash-report
• [ ] I have checked all items without reading.
• [X] I have provided proper reproduction steps
• [ ] I have ticked all boxes

What Minecraft Version is your Server on?

1.20.1

Full Ketting Version

1.20.1-47.2.32-0.2.18

Description of behavior

Warn on first load or every reload. and error occur when click the items in gui that opened by '/ia' commands works fine on mohist

Reproduction Steps

Steps to reproduce the behavior:
1. Install ItemsAdder
2. Install Lonelibs & protocollib
3. launch the server
4. type the command '/iareload' or '/iazip'. Then you can check the warning
5. type the command '/ia' and enter a category and click on any item

Logs

Warn: https://mclo.gs/YZi5zMU Gui Click error: https://mclo.gs/FqV14M8

Additional context

No response

[JustRed23]

I cannot fix a plugin with no source, that also is a paid plugin