Big Business will cancel an Import if it fails to meet needed criteria, such as:
finding a Customer or Default Customer to assign to a Quote, Order, or Invoice
finding an Item or Default Item to assign on a Line Item transaction
This Solution provides suggestion for avoiding fatal errors when importing. (6300)
For Imports with Customers or Items, you can create Default entries to be used when no match is found:
create a new Customer Card that begins with "Default" for its name
create a new Item Card that begins with Default for its Item Code