After upgrading for 2020.4 today I found out parse errors in recipes for custom armor pieces and also when using an armor piece as an advancement icon.
I've recreated the armor from scratch, the error persists. Advancements work fine if I chose a weapon or any other item as the icon, i.e. It only breaks with armor pieces.
I've attached 2 console screenshots showing the errors, also the whole console on a txt file.
The workspace is 170mb, so I hosted it here: https://www.peixelaranja.com.br/tmp/DamianStarWars.7z