Open the corrupted project, and highlight all tracks with ctrl-A (or Edit | Select All). Ctrl-C (or Edit | Copy) copies them into a buffer. Then, open a new project and paste with Ctrl-V (or Edit | Paste). Your project is now copied, and hopefully is error-free. Some aspects of the project may not copy over, but most information will so you can continue working on the project. Remember to save it as a new filename at this point.