A minecraft mod that allows swapping to other in-world screens (blocks, entities, etc) via tabs. A fourth-generation rewrite of CakeWhip's InventoryTabs.
tl;dr: these two things are running in reverse - tick is happening before tags are sent. This really needs to not happen to avoid undefined behaviour, but we can at least prevent the crash.
https://mclo.gs/FxWWlr7 No clue how relevant all of the info in the title is, but...