Zend certified PHP/Magento developer

ISERROR Formula Still Returns ##########

I have a cell that calculates a date using a date and number from two other cells. I have 0s turned off for the sheet and I’m using the following formula to return a blank cell if there’s no data to run the calculation.

=ISERROR(X96-W96-14,"")

It works fine in most of the worksheet, but once I get past rows with data in other cells it returns the result of ############### instead of a blank which seems like an unusual format. All cells in this column are formatted the same. What have I done wrong?

Here’s a link to the file. Reference the ‘Assets Procurement Log’ worksheet, cell F13 as an example of the problem.