I open up my Cubase 4.5.2 project suddenly i receive this message saying, “Missing Ports” i get the option to click either “cancel” or “ok”. (either one i choose does not make a difference).After clicking either of these options, i then get a message asking me whether to remove unused tracks.I then go to check my VST Instruments List and to my surprise its empty.I dont know why this has happened.But i realy need some help as to how i can resolve this problem as the project on which im experiencing this,is very important.Can anyone assist me plz?
Without knowing what your using for your audio (you should post your specs so we know what your using to recieve more targeted and better help) I’d GUESS your audio card (or module) has quit being recognized by Cubase, either because the drivers has gone whacky or something as simple as a bad cable. Make your your device is seen in Windows, (again, if that’s what your using) and the proper drivers are installed. This is a shot in the dark without more info 
As above, but this happens to me with old projects that I created using a different soundcard to the one I’m presently using. I then just assign the outputs to the new card.
I’m using mac. But the main issue is that the instruments along with all insert effect and eq setting etc are all lost. the instruments which i used have all disappeared,which in essence make it the worst thing,because if i cant get cubase to retrieve such data,i would be required to go back inserting effects eq settings etc all from scratch. And if my memory fails me,that makes matter worst. All i have is the midi data,chords etc.I just hope there is some way 2 get cubase to retrieve the instruments i used and their respective settings.
Check your device setup (that’s in Cubase), if it recognises your audio interface, if it has the correct driver loaded and if it can see all your audio/midi IO.
RichardJigz. Your “main issue” in your second post. Sounds like the projects you are creating are not being saved correctly. Have you got incrimental backup engaged as a safety net?
Have you checked the files where you have designated Cubase to save your projects?
We now know your using MAC, but more info still would be helpful
are you missing any of the vst pluggins. i have had this problem and that message with an older project with vstis that i no longer use. ie i had a project with a vsti that i was demo’ing and with VB1. im wondering if it is the vsti’s that are not showing up or hard wired ports from the either the audio interface or midi interface?
if its the former and you have upgraded to the vsti to a newer version perhaps you will need to use the old version.
could you elaborate on some specifics. what version of cubase was the project created on? what vsts are the culprits? ( this is assuming the issue is as i have interpretted it)