It will work fine I'm 100% sure that if your old structure was correctly working it will work again.
Send a new log if the items still don't load even on the old structure and add more details about the issue (provide also screenshots).
About your current CLIENT log:
Using missing texture, unable to load cosmetics:textures/back/cat_tails/white_cat_tail.png : java.io.FileNotFoundException: cosmetics:textures/back/cat_tails/white_cat_tail.png
22:02:58.753
exl
Worker-Main-10
Using missing texture, unable to load iafestivities:textures/halloween/cave_spider_backpack.png : java.io.FileNotFoundException: iafestivities:textures/halloween/cave_spider_backpack.png
22:02:58.757
exl
Worker-Main-11
Using missing texture, unable to load icons:textures/item/next_orange.png : java.io.FileNotFoundException: icons:textures/item/next_orange.png
22:02:58.756
exl
Worker-Main-8
Using missing texture, unable to load cosmetics:textures/back/backpacks/colored_backpacks/turquoise_backpack.png : java.io.FileNotFoundException: cosmetics:textures/back/backpacks/colored_backpacks/turquoise_backpack.png
22:02:58.756
exl
Worker-Main-12
Using missing texture, unable to load festivities:textures/christmas/christmas_tree/green_orb.png : java.io.FileNotFoundException: festivities:textures/christmas/christmas_tree/green_orb.png
22:02:58.754
exl
Worker-Main-14
Using missing texture, unable to load icons:textures/item/white_ring.png : java.io.FileNotFoundException: icons:textures/item/white_ring.png
22:02:58.770
exl
Worker-Main-11
Using missing texture, unable to load texts:textures/items/blank_text.png : java.io.FileNotFoundException: texts:textures/items/blank_text.png
22:02:58.770
exl
Worker-Main-10
Using missing texture, unable to load icons:textures/item/banknote.png : java.io.FileNotFoundException: icons:textures/item/banknote.png
22:02:58.770
exl
Worker-Main-8
Using missing texture, unable to load icons:textures/item/red_key.png : java.io.FileNotFoundException: icons:textures/item/red_key.png
22:02:58.771
exl
Worker-Main-12
Using missing texture, unable to load icons:textures/item/golden_key.png : java.io.FileNotFoundException: icons:textures/item/golden_key.png
22:02:58.770
exl
Worker-Main-11
Using missing texture, unable to load icons:textures/item/next_white.png : java.io.FileNotFoundException: icons:textures/item/next_white.png
22:02:58.772
exl
Worker-Main-11
Using missing texture, unable to load cosmetics:textures/back/backpacks/colored_backpacks/brown_backpack.png : java.io.FileNotFoundException: cosmetics:textures/back/backpacks/colored_backpacks/brown_backpack.png
22:02:58.772
exl
Worker-Main-10
Using missing texture, unable to load festivities:textures/christmas/christmas_candle/fire.png : java.io.FileNotFoundException: festivities:textures/christmas/christmas_candle/fire.png
22:02:58.773
exl
Worker-Main-12
Using missing texture, unable to load cosmetics:textures/back/wings/demonic_wings/demonic_red_wings.png : java.io.FileNotFoundException: cosmetics:textures/back/wings/demonic_wings/demonic_red_wings.png
Can you check your SERVER log to see if these missing textures errors were printed too? The plugin also reports you common mistakes in the log when you run /iazip
command.
Make sure these image files exist, they might not exist in the folder noted.
For example:
cosmetics:textures/back/wings/demonic_wings/demonic_red_wings.png
Should be in any of the sub folders of the contents folders you have for the cosmetics namespace, under ItemsAdder/contents/cosmetics/...
.
contents/cosmetics/resourcepack/assets/cosmetics/textures/back/wings/demonic_wings/demonic_red_wings.png
or
contents/cosmetics/textures/back/wings/demonic_wings/demonic_red_wings.png
or
...check the guide for other structures, the plugin offers a lot of them.