I have created this file and all was ok until I added the 4 small holes inside the blue border. The border is set to Offset Fill. The preview shows the interior all black. If I change the blue border to just Fill, it all looks fine. I did try adding a small offset to the holes, but the result was the same.
Rachael house sign 300 x 200.lbrn (22.2 KB)
The offset fill is a great tool, so hopefully this can be fixed.
Update: this looks the same a s the bug report from Dec. If change the optimisation settings to Layer rather than group, then it works ok.