This error usually occurs because the transaction (Invoice) that is trying to sync to QuickBooks Online is dated in a period that is already closed in your QuickBooks Online account.
The best way to resolve this is to do the following in your QuickBooks account:
Go to Settings ⚙, then select Accounts and Settings.
Proceed to the Advanced tab.
Select Edit ✎ in the Accounting section.
Toggle the Close the books off, or change the closing date.
If you need to change the password, just enter a new password and confirm it.
Select Save and then Done.
Now retry the invoices sync in Anchor. When completed, you can turn the toggle back on.
