Well that is strange because it just happened to me with new project. Saves without any errors but while opening shows me an popup "C2 has stop working". And the best thing is that the backup files from that project opens up normally.
Edit: Ohh, I just renamed project file to test.zip, unzipped it to a folder and from that folder project start with no errors.
If any one has the same issue try this.
- change file extension from *.capx to *.zip
- unzip it to a folder
- run your project from that folder
See if that works for you.shinkan2012-08-28 21:36:52