Help on making custom death loot tables and pack.mcmeta

Hi, I'm new to this discord :):
The problem I'm having is that my custom DeathLootTables don't work at all. When I summon a zombie with the DeathLootTable "zombieone", it drops only EXP and nothing else. Can anyone help??
Another thing is that my pack.mcmeta always outputs a error message (also in link) and I don't know how to solve it.
Note: I posted this question on reddit (Cuz Y not) so please look at it and refer to most of it, link here:
https://www.reddit.com/r/Minecraft/comments/17yn2i4/help_on_making_a_minecraft_loot_table_why_doesnt/k9umo3c/?context=8&depth=9
Thanks everyone!