It doesn't seem difficult to understand, the model you use to create the mirror (which is asked with a window) has inside a body. or change model or correct what you want to use
You don't understand anything from your explanations.
open the template or template that you want you to use to make mirroring and verify that it has no bodies.
so much to twist, the simple mirror does not require a template to be selected because it always uses the same geometry. the opposite hand mirror must create a speculative geometry and needs a template from which to generate it; if instead of stopping at tab 2 go to 3 and specify them. create a configuration, no template is required because the model already exists
when you do not specify to create a configuration, a window opens with the choice of the template. (window equal to that which appears by creating a new file)
No. doesn't create any window with template choice. Shoot me out. It puts me that notice, and then the primary piece disappears from the same time and you do nothing. between the other then I have to restart the program because it no longer opens any files. not from mistakes but does not open them.