1. Working in a network environment.
2. My dependent workbook in one subdirectory links to several source
workbooks all in one other directory (this has never been a problem before).
3. All such linking formulas show "#REF!". But everything worked fine last
week when I created the dependent workbook with its links.
4. Formula in dependent workbook is:
SUM(INDEX(...BLAH...BLAH):INDEX(...BLAH...BLAH))
5. I have used TOOLS/FORMULA AUDITING/EVALUATE FORMULA to confirm that the
INDEX arguments within the SUM formula each evaluate to the proper cells in
the source workbooks. In other words, I proceeded through EVALUATE FORMULA
until I got
SUM('path\[filename]\worksheet'!$C$27:'path\[filename]\worksheet'!$J$27) and
the next EVALUATE step produced the "REF!".

Any suggestions?
Many thanks,
Stephen Powell