I'm using create in a modpack and on the updated version, it crashes when I place more than one shaft together. I reinstalled the older version and it worked just fine. I don't know if this helps but the error was: java.lang.IllegalArgumentException: Invalid hand null.

Do they need this:<script src="https://pastebin.com/embed_js/Nwawd2vA"></script>
or this: https://pastebin.com/Nwawd2vA
Never used pastebin before.

Yes, that is what helps and that second link works, but you can also use (markdown I think) and format it like [text-to-display](url) cause github doesn't use html like other forum sites.

And from reading your crash try updating to the latest version of optifine, some others have had other crashes or issues related to out of date optifine.
If that doesn't work see if it happens without optifine or without shaders

Almost always devs need the entire crash log, preferably uploaded to a site like pastebin and linked.

It still crashes without optifine, and I have the latest version of optifine. I also wasn't running any shaders.

Mod incompatibility was the issue.