No amount is displayed for a vendor in the Review 1099 Forms Before Printing window
It's likely that this vendor has not been designated as a 1099 vendor. (To set up a 1099 vendor.)
If you want remove the vendor from the list in this window, mark the 1099 Vendors Only selection in the Advanced Filters window. To manually enter amounts for this vendor and print a 1099 form, click the zoom arrow next to the vendor's name. (To enter or change 1099 income amounts)