Steps to Reproduce the Crash

The game crashes intermittently when I open my inventory. It freezes for a few seconds when it happens.

Mod Pack URL (Optional)

https://www.feed-the-beast.com/modpacks/103-ftb-skies?tab=about

Mod Pack Version (Optional)

1.5.0

Extra Notes (Optional)

No response

Crash Report

https://gist.github.com/cdubs808/bea2e26efcf1555105e4fb1f7fcf1e68

Same error, same modpack.

https://pastebin.com/U5r6FmPm

exact same thing happens to me, but for Better Minecraft 4 (BMC4), and also when i press ESC

https://www.curseforge.com/minecraft/modpacks/better-mc-forge-bmc4

Thanks for the report!
This is coming from com.blackdragonfire.flowerdoubling
https://modrinth.com/mod/flower-doubling/version/LrUognnq

It seems like a closed-source mod, and I don't know where to report bugs to them.
I will try catching this type of error in JEI and logging it instead of letting it crash.