You said, your project is 30 tracks, and you are trying to export them one at a time.
Question: WHY, export one at a time? Exporting to what file type? Are these all midi files with soft synths added?
For a file to be exported individually from a 30 track template, would need to have all the tracks starting at the begining of the recording to be useful to import back to your template. Otherwise, if you want the 30 tracks as is and as a template, save them as an OMF file, and you can open OMF templates with Sonar, and other DAW's support OMF's.
All audio tracks will be saved as is in an OMF file, however, all midi tracks have to be saved as individual tracks in an OMF. OMF saved files not bounced will not have the effects included.
If you are trying to export as wav files, I suggest you go 24 bit, with no dither.
If you are trying to export an MP3 for a CD, it will have to be 16 bit, and I suggest you do that at 192 or higher, and use Triangular dither.
The files need to be audio files. Bounce each one seperately to an audio file, and store the midi file in a track folder. I am not much of a midi user. If your are more specific on exactly what your end result is that you are trying to achieve, maybe I can be of more help.
I assume, when you click export, it is having to run 30 tracks of synths in memory and that is causing the crash. If worse comes to worse, open a new project, and copy past them to the new template one at a time, and then export each one, then empty the new template and start over for the next track. Make sure the tempo is the same. You can drag your effects over as well. Open the 30 track tempalte, and a new template one beside it. Hard work around, but it beats losing your data. So many things could be happening, but I suspect over CPU usage. Are many of these track sharing buses? If so maybe you would want to drag over or copy past as groups for the work around?