Error when "Saving project As"

What is the reason of showing err message “You can’t save the project into a current project!”, when I use the “Save As” project to the folder which is complete empty?
The project is fresh new created.

Hi,

This message appears if you try to use “Save As” to save the project in the same folder where it’s originally located. You can use “Save As” to save the project in an empty folder.

Thanks for reply, I found it meanwhile. It is not possible to save the project into any slave (even empty) folder created within the folder, where some project already exists.