Note: Delete the following 2 lines when you submit the issue.

• If this bug occurs in a modpack, please try first reporting it to the modpack author. Barring that, please narrow down exactly what other mod(s) are responsible for the issue.
• If this is a feature request, this template does not apply to you. Just delete everything and write what you need.

Issue Description:

After add roboticraft to the modpack，it crashed during loading。

What happens:

What you expected to happen:

Steps to reproduce (important):

1. https://paste.ubuntu.com/p/xDNc6BHj69/
2. If remove roboticraft，there is no error。

...

Affected Versions (Do not use "latest"):

• IronBackpacks: 3.0.8-12
• Minecraft: 1.12.2
• Forge: 2703
• Other Conflicting Mods (may be irrelevant to your issue):

#237