Your loadout may also have contained a cosmetic item that has since been removed from your inventory. For example, we all got granted the Fatshark Dev portrait frame a while back, I equipped it, and when they fixed the issue, my loadouts that had it got the red exclamation point over it. I changed the frame to something other than what it defaulted to and it went away.
Oh, I’ve just remembered, I also see that red exclamation point when you’re missing an item from that loadout. You may have bartered a weapon or sacrificed one to Hadron, sold a trinket, or a talent was completely changed - as in, not just “tweaked a value”, but presumably an entirely new talent with a different internal ID replaced one you had before, like a few Psyker talents in the past, amongst others. This also ties in with the missing cosmetic I mentioned before.
I can’t confirm the talent thing, but I’d like to think it’s a decent guess.
That’s probably correct about the talents tbh. Both of those builds of mine haven’t changed in a while and they both have Wrack and Ruin equipped, which was buffed a couple of patches ago. I’ve been using a different build for a while so I must have just not noticed it before.