Question

I can't change the instrument in the existing track except the ones already used in different tracks within a song.

Here's the situation. I opened the song and the message "missing instrument" pops up. I  went to that track and need to replace the instrument that no longer exists in my library on a new one which I just installed.  In studio one 5 I have to go to the instrument browser , drag the instrument into the track which sometimes ends up in creating a multiple instrument.  I want to be able to open the list box on the instrument track and choose the instrument I want, not those that already used.

Answer 1

Drag the new instrument where you want.  If there is already an instrument on the track (Presence Xt for example) you should get the choice to either replace or combine.  Choose replace.