What that red text in your cell actually means
Excel error messages are short for a reason — but short doesn't mean clear. Pick a code below or use the dropdown for the full breakdown: meaning, the most common real-world causes, and a copy-paste fix.
#DIV/0!
#N/A
#NAME?
#REF!
#VALUE!
#NUM!
#NULL!
#SPILL!
#CALC!
#GETTING_DATA
#FIELD!
#BUSY!
Pro habit
One rule that prevents most error-debugging sessions
Don't wrap everything in IFERROR by default. IFERROR swallows the message — including bugs you actually want to see. Only wrap the outermost part of a formula, and only when you've already understood why it might fail. A formula that occasionally errors is louder, and easier to fix, than one that silently returns an empty string.