Pardon the last post — it looks like the issue is with the _DEREF_OPT error in the screenshot above, which is mentioned on this page:
A somewhat of a documentation of hidden formulas [Added mechanics of nested buttons]
_DEREF_OPT— “Dereferences the given input with the given reference”
When I have a LOOKUP column with nothing selected, the concatenate breaks and gives the above _DEREF_OPT error
anyone have an idea of what to do with blank LOOKUP cells?
I’ve been toying with adding toText(), ifBlank() and different things to my concatenate but no luck so far
apologies for this sloppy thread, I’m pulling my hair out trying to figure this out