The package comes with a Inventory database. This button is enabled only when results exist. Clicking this button in the results page will automatically
If you have updated the inventory for a project once, you should not do it again. To prevent multiple updates of the inventory for the same job, the button is disabled once the inventory has been updated.
The updated inventory position can be seen by selecting the "Tools->Manage Inventory" menu.
PS: You have to save the file to ensure that the information that the inventory has been updated is written into the file. Next time the file is opened, this button will be disabled.