This error message means at least one of the Inventory Type Items on the transaction has an initial Quantity on Hand in QuickBooks Online with an "As of date" that precedes the transaction date.
It is important to note that if you have an inventory-type product in QuickBooks Online, then you cannot record a sale for the product before the date you actually had the product available. For example, if an inventory type item in QuickBooks Online has a start date of 10/01/2020 then you cannot record a sale for that item with a prior date like 10/01/2020.
To resolve this issue, log into your QuickBooks Online account and follow these instructions:
1. Click the Gear icon, then choose Products and Services.
2. Look for the inventory item and click the Edit button.
3. On the Quantity on hand, select Adjust Starting value.
4. Click the Got it button, then update the ConnectWise transaction date, or update the Inventory Starting Value for any items on the transaction that fall after the ConnectWise transaction date.
5. Hit Save and close.