To avoid busybusy integration from failing after a QuickBooks software upgrade (good to get a notification), please follow these steps:
Step 1: with QB open, open the connector and remove the busybusy application.
Step 2: go to edit >>preference >> the integration application >>company preferences and remove busybusy application.
Step 3: upgrade QB.
Step 4: restart your computer
Step 5: go to busybusy disconnect and refresh the page.
Step 6: Download a new busybusy.qwc file.
Step 7: open QB. Open the connector and add a busybusy.qwc file.