“But because of how references get saved into assets (it’s just a list)”
Which is presumably a caching optimization? Does that list include indirect referencers?
“try creating a new MIC and see if it reproduces for that.”
Can’t, that function was removed from the base mats a long time ago.
" If it doesn’t, then the Material might’ve been created in an earlier engine version and has since been fixed."
Yah base material was probably created in 5.2 and we are on 5.5 now, the function was removed from it long time ago probably 5.4 or earlier.
Yes I couldn’t repro it again either, and remember I said that when I resave the MICs, the issue is cleared. So maybe it was an issue of a stale cache of referencers being naively used by the reference viewer, where the direct referencer is gone so it was only a list of irrelevant references left?