Some users will see the message "Invalid Barcode" on their Print Preview when trying to view the layout of their label design with a barcode on it.
If you are trying to produce a UPC barcode, this message can occur when the number you typed to create the barcode is 12 digits instead of 11. You need to type just the first 11 digits; the program will add the 12th digit on its own. This last digit is the "check digit" and is calculated by the program from the initial 11 digits of the code.
Take the 12th digit off and do a Print Preview, and the program should generate the barcode and stop displaying the Invalid Barcode message.