Thanks for your help, but the guidelines you gave me are not entirely true, if not, let's see:
1) I have a certain instrument that has only 2 audio tracks and one mid.
2) Both tracks have only volume automation.
3) Select only those tracks, including the folder and do an Edit -> Copy
4) I go to the project where I want to copy and command Edit -> Paste and the result is the one below. The destination project was empty.
5) Now, if in the destination project I insert an audio track and proceed with Edit -> Paste what happens is as below. That is: it only makes the copy if it has a specific audio track to receive the first track of the instrument in the initial project