According to my sources the issue lies with the Goo mod. The issue is that whenever anyone on the server attempts to open a guide book, be it from Botania, Ars Nouveau, Nature's Aura, Industrial Foregoing, etc, the game immediately crashes to desktop.

It would help if you provide a log, since there is very little that can be done without one.

FC1 is running every single one of those mods and goo and this is the first I've heard of it, so I'm skeptical. Let's see a crash log, please.

For what it's worth, Goo doesn't do anything spectacularly interesting with its Patchouli book other than implementing a dedicated item rather than letting Patchouli make one for it. That dedicated item is also a firm point of separation between Goo's patchouli book and anyone elses. There's no mischief. It's just consuming the API like an average Joe.

crash-2020-11-02_21.40.29-client.txt

I'm not seeing anything in the crash log to indicate it's Goo. So I started up a server and connected to it as a client, and gave myself a book, and right clicked with it. It opens just fine.

What's the source's test criteria to inform them this is Goo's crash?

Does it only crash when opening other mod guide books?

any guide book causes the crash. Attached is the log from trying to open the Goo and You guide book.
crash-2020-11-03_08.25.47-client.txt

@Allyraya Could you please remove goo from your pack and try again?

crash-2020-11-03_12.44.37-client.txt
I did not assemble the pack, but I have tried to do as you asked. I had to load a single player world, so I do not know if it worked or not.

@Allyraya Yeah, log shows Goo is gone, so whatever is causing the issue, it aint Goo that does it....

Alright, thanks for the assistance, I will let the modpack curator know. :)

me and @valkrieofnight already aware if this @Allyraya

Thank you guys; I'll close this, for now. Feel free to let us know if we need to revisit.