Hi @bsrawal1970 ,
@pramodQ4FRF is correct. In your case it seems that you have bodies that you have selected when you created the setup, which lie outside of the build volume. This will cause the toolpath generation to fail. To resolve this, please place all parts inside of the build volume.
Please also see my attached images detailing what the Fusion 360 Additive workspace part colour-coding represents:
Part is outside of build volume:

Part is close the build volume boundary:

Part is inside of build volume:

Therefore, you should be seeing red parts somewhere outside of your build volume. Check your part's visibility if you cannot see them.
Send your project through and I can take a look if you need.
If my answer has helped you, please click "Accept Solution".
If not, please reply back and tag me.
Thanks,
Tom
Fusion Additive Team