I'm working on a resource pack. I've made some changes to the GUI pngs (inventory.png, brewing_stand.png, etc) and I've put them into my resource pack in the correct folder: pack/assets/minecraft/textures/gui. The rest of the pack works perfectly! However, the GUIs do not take effect. I just get the plain grey standard GUIs for inventories and chests and such.
Can anyone help me understand why this is happening and how to fix it?