Placing Nagastone Head (id 848) crashes server

[kerrytazi]

Your GTNH Discord Username

kerrytazi

Your Pack Version

2.6.0 beta 2

Your Server

private server

Java Version

Java 9

Type of Server

Don't know

Your Actions

Trying to place Nagastone Head (id 848) block (from The Twilight Forest) causes server crash. After restart block is placed and duplicated in inventory.

Crash Report

fml-server-latest.log <-- Error starts at line 44777.

Final Checklist

• I have searched this issue tracker and there is nothing similar already. Posting on a closed issue saying the crash still exists will prompt us to investigate and reopen it once we confirm your report.
• I can reproduce this crash consistently by following the exact steps I described above.
• I have asked other people and they confirm they also crash by following the exact steps I described above.