Can I use a relative adverb “where” when “case” or “instance” is an antecedent?
“case” and “instance” is not a location, but I have seen “a case where” and “an instance where” a lot.
Where is not only used for location:
1 b : at, in, or to what situation, position, direction, circumstances, or respect
// where does this plan lead
// where am I wrong
3 b: at or in which
// has reached the size where traffic is a problem
// two fireplaces where you can bake bread in the ovens
— Randall Jarrell
4 b : in a case, situation, or respect in which
// outstanding where endurance is called for
5 : THAT
// I’ve read where they do it that way in some Middle Eastern countries
— Andy Rooney
There is nothing at all incorrect about using where when in any of these constructions. It does not need to be used only for a place.