Versions:

• Curious Elytra: curiouselytra-FORGE-1.15.2-2.0
• Caelus: caelus-FORGE-1.15.2-2.0-beta2
• Curios: curios-FORGE-1.15.2-2.0.2.2
• Forge: 31.2.0

Observed Behavior

No cape present until an elytra is put on the curios slot.

Expected Behavior

Cape should be visible without an elytra. Putting an elytra on should hide the cape.

Steps to Reproduce

1. No elytra equipped = cape is never visible.
2. Put on an elytra in the curios slot = cape is show along with it's pattern on the elytra.

Other mods (necessary to reproduce the bug)

• OptiForge-MC1.15.2-0.1.19
• OptiFine_1.15.2_HD_U_G1_pre18
• MixinBootstrap-1.0.3

Additional Info

Putting an elytra on the vanilla chestplate slot doesn't show the cape but does show the cape pattern on the elytra, same behaviour present with only Caelus-Forge installed, no cape is shown at all even when equipping an elytra, altho the cape pattern gets applied to it.

Documented on illusivesoulworks/caelus#5
Please follow there for further updates

Hmm, just so that I've got this right:

With only Caelus, Forge, Optifine, Optiforge, and MixinBootstrap:

1. Capes never appear even with an elytra in the chestplate slot
2. Elytras gain the correct cape pattern

With all of the above + Curious Elytra:

1. Capes do not appear unless you equip elytra into the curios slot
2. Elytras gain the correct cape pattern

Is that correct?

I'm not really familiar with capes so I need to ask first, are you using an official cape or obtaining it through some other method?

It's an OptiFine supporter cape, anyone using OF can see it, mine uses a banner pattern.
Afaik they work just like official ones, don't think I got access to an official one to check tho.

Yes, that's correct.