When i have a zz exported workbook open, minor action in other excel sheets crash the app. This is the error. It is occurring on several workstations in our office.

Hey John, thanks for reporting. Could you send the Excel File to support@zztakeoff.com or our website support so we can take a look at it on our end? Doing a quick search online, this could be an issue with too much styling embedded in the Excel sheet, or your font cache in Windows could be corrupted.