Link a file to a Pivot Table in another file
 

I have a sumamry file for monthly reporting that is linked to four different
files (each with a pivot table). With all the files open, I refresh the data
of each pivot table, save them and voila! the summary file is updated and
saved.
**The issue I have is when I close all the files with pivot tables, the
summary file shows me "#REF" in the cells with the links to teh tables. Not
sure why, any ideas are greatly appreciated!