Please can someone help me in solving for this error in robot structural analysis? "there are no nodes in the floor plane"

I did everything but, even redo the whole thing again but this error keep appearing, “there are no nodes in the floor plane” Please can someone help me with it?

Hi Dave, can you please post your question in the Q&A section, which is right underneath the video lesson and the instructor will answer it asap.

Okay. I will do that. Thank you