Labor Distribution by Timecard; How to process OTL timecards having Project and non-Project hours

Summary:

Our organization has a mix of employees who allocate all, part or none of their time to Projects.

From an OTL perspective, some hours are charged to the home or default cost centre, some hours are charged to Projects.

When importing time entries from Oracle Time & Labor, the Project related entries are successfully imported with a cost of $0 (as expected).

When importing and processing Payroll costs, we are receiving an error "There aren't any eligible target time cards to be processed." We have not found any specific documentation to explain the reason for the error, however, observation suggests that this happens only when some hours in OTL are not entered with Project details.