if you try to open a project as normal "a new project".
is there any problems ?
you could have some plug ins that are failing to load.
you could try holding Shift while opening sonar.
this is known as "Safe mode".
https://www.cakewalk.com/Documentation?product=SONAR%20X3&language=3&help=Dialogs2.094.htmlif you are having a plug in issue this will let you know.
if its "Missing audio" you are referring to, well that's a little different.
simply navigate to the correct folder where the missing audio is and load the files in 1 click.