Created attachment 34910 [details] File from Euses spreadsheets corpus When attempting to parse Excel formula SUM(#REF!:#REF!) with apache.poi.ss.formula.FormulaParser.parse, it throws exception: org.apache.poi.ss.formula.FormulaParseException: Parse error near char 9 ':' in specified formula 'SUM(#REF!:#REF!)'. Expected ',' or ')' A real-world example taken from the Euses spreadsheet corpus is formula SUM(AC12:AC15,AC17:AC20,AC22:AC24,AC26:AC29,AC33,AC35:AC40,#REF!),AVERAGE(AC15,AC17:AC20,AC22:AC24,AC26:AC29,AC33,AC35:AC40,#REF!:#REF!),"") in the attatched EC101Grades.xls::Gradebook!AC43