Join and Loft not working in Grasshopper

I am trying to create solar envelopes in Rhino using Grasshopper but the output commands don’t seem to work. The join and loft commands pop up with these error messages: ‘insufficient curves for joint operation’ and ‘null profile curve was removed’. I am new to Grasshopper so still trying to understand the software, please help!

Hi @Aroma_Imran
Welcome to the group. It could well something fairly simple, but in order for one of the Grasshopper proficient users to help you, we need more than just a couple of screen grabs, as they really don’t say much in terms of data flow. Read this clear description of how to ask effective questions and make it easier for others to help you.
HTH, Jakob

Look at the wire connected to En output of the Brep Edges component. The orange color indicates that it is empty (the brep connected to the B input of the Brep Edges component has no naked edges).

If you need further help, upload a grasshopper file with internalised geometry.

If you follow the guidelines at the link @Normand posted, you will be more likely to get your questions answered.