@damaiyanto said:

but then if it is the light cache , does it mean there's no hope for using it?

If you figure out which materials are slowing it down, you could try adjusting those problem materials (fewer subdivisions, use bump instead of displacement, etc.) then try LC again.

Here's my result - it's fine.Capture.PNG Can you post the problem SKP here ? You haven't 'grouped' the lines etc have you ? What happens if you answer 'No' ? Do you get any errors in the Ruby Console when doing this ?