Error

Explanation

This error occurs when the "category" field in Oracle NetSuite is a required field for a vendor. 

Solution 

Make sure the category field option is not mandatory in your default vendor form in Oracle Netsuite. You can find this in Oracle NetSuite:

1. Customization > Forms > Entry forms > locate the preferred Vendor Entry form and click Edit
2. Click on the Fields tab, then click on the Information sub-tab and uncheck the box in the Mandatory column for Category

OR 

If the mandatory field must be enabled, create vendors in Oracle NetSuite and let them sync into Bill.com.