ClientboundContainerSetSlotPacket setting nbt on an ItemStack object results in an Internal Exception by the client (1.20.1 latest)

[EpicBirb]

repeat of #746 but for 1.20.1 (latest build from the repo)

removing the nbt from the packet results in the client saying "Joining world"

[EpicBirb]

also when can we get a documentation for the library?

[Konicai]

What kind of documentation are you referring to? Packets and network data are almost certainly better covered by wiki.vg.
If javadocs are lacking then I understand.

[EpicBirb]

javadocs