how to resolve this problem?

The picture says everything.
Every help is welcome ;)
Down image with name "not_working.png".

4 Answers

It is difficult to resolve complex problems from a screenshot.
I have two suggestions:
1. upload your part file so anyone helping does not have to recreate it.
2. Instead of trying a Boss-Loft, try a Surface-Loft. It may not work, but surface lofts are more forgiving in many cases.

try to change the green connector position of sketch 5 to the upper right corner,
also please note that you have intersection of the two sketches when they follow the spiral as a center line,
hope this help

if you are trying to make a turbo charger please refer to this link and you will find the solution for you problem
good luck

You can upload files directly in the Question section. No need to place them in the library.
Maybe the way you've drawn it could work (as evidenced by the video Nabil posted above), but it is not a "good way" to start a model.

Simplify the process.
Instead of dealing with a loft between two rectangles, work with two lines.

Your guide curve / centerline should be repaired as well. It does not technically have to start and stop on the loft profiles, but it should.

A screenshot is attached.