This occurs when the starting check number is not defined on the bank account.  

Define the starting check number:

  1. From the Banks page, click Edit Account Details.
  2. Select the Payments tab.
  3. In the Manual Check row mark the Allow? checkbox or ensure the option is marked
  4. Select the appropriate Numbering option from the drop-down menu.
     
    • If selecting Start With, enter the appropriate number in the Next Number column.
    • If selecting Same Range As, select the appropriate option from the Next Number drop-down menu. 
       
  5. Save and Close Edit Account Details.