There is no reference available for hr.timesheet.group (V6)

Hi,
We are looking to evaluation the recurring invoicing module. We're running V6. Here's the steps we did:
Import the zip file as a module
schedule for install
run module install
It then gives this error "There is no reference available for hr.timesheet.group"
Any ideas?
Thanks
M. Payne
We are looking to evaluation the recurring invoicing module. We're running V6. Here's the steps we did:
Import the zip file as a module
schedule for install
run module install
It then gives this error "There is no reference available for hr.timesheet.group"
Any ideas?
Thanks
M. Payne