You have probably generated a circular reference.
The reason? How should we know without knowing your script nor your data??
So prepare yourself for a serious debugging-session. The following hints may be helpful:
- try to compare last weeks data with the current one - are there any special values?
- and compare the amount of data - do you have more this week? And are you now crossing some hard-coded limits?
- check all cells containing formulas - either in your excel-sheet or formulas written by your perl-script
- check all cells referencing other cells: are some constant rows/columns referenced (which might now be overwritten by your script?)
- try to "simulate" your script by hand, so you might find out when the circular reference occurs ... and if it is due to some data already present in your excel-sheet (e.g. a reference or a macro) or due to your perl-script
- generate a lot of debugging-output to localize where the error occurs
Good luck and happy debugging
Rata
PS.: don't forget to prepare a sufficient amount of coffee to support your efforts ;-)