Bungie Answered
Weapon mods in Armory no longer show they're equippable (arrow icon)
I have Scar equipped. Tooltip shows that the mod fits the gun, but the icon itself has a cross icon, as if it doesn't. Tested and it's the same across all guns.
Mods in Vault and Backpack work correctly.

1
Comments
Hi there,
Thank you for reaching out and for reporting this.
Could you provide a few more details to add to your report?
If you have any videos of this happening in-game, can upload the footage to a public video hosting site, like YouTube, then post the link here and we’ll be glad to take a look.
Known Issue unfortunately, we’re working on it.
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