Was testing a Mod pack one mod at a time to find issue
Mods installed and all were rendering:

• Alex's Mobs (dependency of Citadel)
• Floral Enchantment
• VIllage Employment
• Curios API (Forge)
• Cosmetic Armor Reworked
• Backpacked

As soon as I installed, the other mods no longer show on the player and show as a pink or pink/black box. Immersive armors would show on player.
Was just on a superflat creative world.

Cosmetic Armor works for me, can you specify the incompatibility with it?
Backpacked works fine too.

I tracked down the issue with missing textures, will get fixed soon, thanks for the reports!
If errors remain after 1.0.1 please reopen this issue.

The error happens because Forge is doing some fancy extra stuff which I overwrote. Since I also support Fabric the fix is a little bit harder.

from other Report: Twilight Forest, Ice and Fire, Nautilium, Create, Atumnity and Yurina's Enderite Mod

So sorry I didn't check this yesterday, my dear mod author! First, THANK YOU for the mod, I really love it. Thank you for caring to bug fix!

Cosmetic Armor works for me, can you specify the incompatibility with it? Backpacked works fine too.

I apologize, those mods were working for me too, I just wanted to include that they were installed in case they were the issue.