When you try a apply a Number Format or insert a Chart into your workbook, a message saying "Unable to Set the NumberFormat Property of the Range Class" appears.
This issue is caused by a limit on the number of custom number formats per Excel file. Excel keeps adding new ones on your request but never deletes them when they are no longer used. You can check the file number format by opening the Cell Styles window.
If you have access to our Modeling Tools option you can use the Clean function to remove all unused cell styles on the file and this will also remove the number formats.
Make sure that the Option "Remove all unused styles" is checked before applying the clean.
If you don't have the Modeling Tools option, you can either delete each Number Format manually or use a tool called XLStylesTool, available on the Microsoft Store.
Open the software, load your Excel File and Clean the file using the "Process File" function:
If you still have issues with this error message after cleaning your file, please get in touch with UpSlide Support by using the "Contact Support" function.