Description of the Bug

While testing 1.6 in the multiplayer server I encountered a crash when switching from the advanced Science tab of the quest book to the Intro to Science tab of the questbook. I was not able to replicate this crash.

Expected Behaviour

1. Click on Intro to Science tab of questbook.
2. Basic Science tab of questbook opens.

Modpack Version

1.6

Screenshots

No response

Log

https://pastebin.com/hnyTi1Jt

Extra Info

No response

Java-level crash, can't do anything with that log.
If it was just a one-off, leave it as a one-off, especially if it was Java-level.