The bug

If you've got an item with an unknown block tag in the CanDestroy or the CanPlaceOn NBT, the game crashes when hovering over the item.

How to reproduce

1. Give yourself an item with either the CanDestroy or CanPlaceOn tag

   /give @s minecraft:diamond_block{CanDestroy:["#minecraft:planks"]}

2. Disable the vanilla datapack (to make the #minecraft:planks tag unknown)

   /datapack disable vanilla

3. Hover over the diamond block item → the game will crash

   Description: Rendering screen
   
   java.lang.NullPointerException: Rendering screen
   	at aul.f(SourceFile:725)
   	at aul.a(SourceFile:678)
   	at cjn.a(SourceFile:99)
   	at cjn.a(SourceFile:95)
   	at ckr.a(SourceFile:680)
   	at cki.b(SourceFile:177)
   	at ckr.a(SourceFile:637)
   	at ctg.a(SourceFile:821)
   	at cfv.c(SourceFile:820)
   	at cfv.a(SourceFile:381)
   	at net.minecraft.client.main.Main.main(SourceFile:143)