There are three methods that the user can try to recover a corrupted PTW project.
1) Hold down the Ctrl & Shift keys when opening a project. This will cause PTW to automatically validate the database. Note: This will also work to when opening one-lines.
2) Run the database utilities from the Project pull-down menu (project must be closed first).
3) Merge the corrupted project into a blank, new project (must create blank project first before running the project merge.