Errors of components in grasshopper

Yes. Or you can internalize geometry in the GH file so the Rhino file isn’t needed.

Apparently you missed this on the list of tips about How to ask effective questions

3. Attach minimal versions of all the relevant files
If you have a gh file you have a question about, attach it to the post. Do not expect that people will recreate a file based on a screen-shot because that’s a lot of pointless work. It’s also a good idea to remove everything non-essential from a gh file. You can use the Internalise Data menu option to cut everything to the left of a parameter:

If you are referencing curves or breps or meshes from Rhino, you can also internalise them so you won’t have to post a 3dm file as well as a gh file. If you’re unsure whether all the relevant data is internal to the gh file, try opening it in an empty Rhino. Does it work? Good. No? You’ll need to internalise more.

Flatten is not the only way to fix the problem. It will cause many models to fail completely, since preserving the tree/branch structure is often necessary. That’s why I mentioned Clean Tree and Prune Tree as alternatives in this case. Shift Paths is another very useful component to avoid flattening a tree in some cases.

Understanding your data trees is essential to success with Grasshopper.