Why the sync error occurs
This error occurs when a deleted account is trying to sync to QuickBooks Online from Bill.com, and the account is set as a Retained Earnings account in QuickBooks Online. QuickBooks Online doesn't allow Retained Earnings accounts to be deleted.
How to Fix the sync error
The Retained Earnings account can't be deleted or edited in QuickBooks Online. The only options are to reactivate the deleted account in Bill.com or to contact Customer Support to clear the error.