Explanation of behavior: I left-clicked a plant item(in this case, I tried both a brown mushroom and a piece of coral) in my inventory while a flower basket was also in my inventory; the client immediately crashes.

I also recently updated Quark, which has a changelog mentioning a fix to the inventory drop-in behavior with shulker boxes; maybe something changed that also happened to break your integration code?

Mod versions:

cuneiform-1.16.3-1.2.5
terraincognita-1.16.3-1.7
AutoRegLib-1.6-49
Quark-r2.4-312

Crash log: https://gist.github.com/Febilian/2497d4847fca8119838f5e881cf7e8c2

Fixed in the new beta!

Any eta on when this will get fixed? I was wanting to play with terra incognita alongside quark but I still can't use the basket.

Sorry that it's taking so long, I'm currently busy with some IRL things and a bit stuck on the code.
I've already fixed this issue and will try to finish the 1.6 release soon!

I don't know if this one is specifically with quark, but I am crashing when picking it up from the creative inventory.

Here is the crashlog:
crash-2021-06-16_00.18.05-client.txt

The IDropInItem interface changed. Two of the methods take an additional parameter now. It's an easy fix, at least...