You can either try running Audit....or you can submit a ticket to Autodesk and attach the file...or....try opening a backup file.
If you are on Subscription, and are authorized to submit requests under that Subscription account, you can log into your account at https://accounts.autodesk.com/, choose the Management link at the top of the page, and then use the Support drop-down list at the top of the Management page and select the View my support cases link. That will open a new tab that will allow you to create a new support case.
Indicate that you have a corrupt file that Audit did not fix. The support person handling your request will provide directions for uploading your file to an FTP site.
@Anonymous Who is your support contract through? Autodesk or are you with PacifiCAD? If you have issues you should contact one of them, not ask for immediate help on a public forum.
BTW, I am in CdA too...