The first step to correcting any QuickBooks sync error is to remove all invoices from the Ready To Sync queue and run, what we call, an empty sync.
The purpose is to ensure there are no other underlying errors that may be contributing to the currently visible error in your QB error log.
It is highly recommended that you correct any errors that arise during the empty sync.
[Resolving QuickBooks® sync errors]
This "Object ID" error typically does not hinder the sync process but could be a sign that there are other issues needing attention. You should be able to ignore these "Object ID invalid" unless your intended invoice is not syncing or you have data in QuickBooks that is not transferring into Kickserv.
In this case, you would want to make note of the error message and search for it on our help.kickserv.com site or submit a support ticket.