I had this a very similar thing occur on a recent X1 project, as well. I submitted a problem report (CWBRN-4328) with the dump data and the response was:
"... We believe that the problem you are experiencing is most likely a system specific problem or a configuration issue that can be resolved with assistance from Cakewalk Technical Support. Unfortunately, as explained in the Problem Report Form, this form does not put you in direct contact with our support staff.
Please contact our support team at
http://www.cakewalk.com/support/email or at (617) 423-9021 Mon-Fri 9:30 am to 8:00 pm EST so that we can assist you in resolving the issue you are experiencing.
We thank you for your support, and we thank you for choosing Cakewalk."
So your best bet is to call tech support to see if they have a way of extracting the MIDI data from the project, which would be a really nice thing to know, actually. But DO submit a problem report so they can begin tracking events like this. Fortunately for me, my project was just starting to get beyond a quick demo, but considering my frustration, I can imagine having an entire project become corrupted.
Good luck!