Understanding error in geometry

Can you tell please, what means for example this error ?

Снимок экрана от 2022-02-15 20-08-24

I just want to create hollow cylinder.

Also when I define the region of AIR it shows error too

Photoyields.inp (11.6 KB)

Dear @sergey.a,
As soon as I open your input in flair, I get a popup warning me of an error:

If I click on the button in the popup, I’m redirected to the Output tab where there is a pretty clear error message:

You are using an invalid body in the definition of the AIR region. Indeed, the body “i2” does not exist in your input. There is instead a body named “Ni2”.

I would recommend you to always read the error messages you receive. They aren’t always cryptic and instead can prove themselves useful.

Thank you very much. I should try to be more attentive. Can you please answer on my first question too ? About this errors

Снимок экрана от 2022-02-15 20-08-24

The first line of each error indicates the position of the error. In this case, error#1 occurs at x=1, y=0, z=1.5.
Body indicates which body is involved in the error, in this case “Col”.
Reg- and Reg+ indicate respectively which regions are on the “minus” or on the “plus” side of the body (look at the geometry lecture for the meaning of “minus” and “plus” of a body).
In your specific case, the problem is that the portion of space around the elements of your geometry do not belong to any region, this because there is the aforementioned error in the definition of the region AIR. Please, note that even if you fix this error, you will have still at least one problem, i.e. the region COL is made of a finite cylinder that includes everything that is inside, including in particular the portion of space that you have assigned to the region HOLE.

Have a look at the Geometry Editor lecture to see how you can build your geometry directly in the graphical interface. In this way, it would be easier to avoid problem like this.

A post was split to a new topic: Question about example in geometry editor lecture