Repair Inaccessible Outlook OST File

My main Outlook data file (.ost) suddenly refuses to open, and every quick-fix I have tried has failed. I need someone who knows the inner workings of Microsoft Outlook data structures to bring the file back to life and return all my mail, contacts, and folders exactly as they were.

Here is what you should know:
• The file belongs to Microsoft Outlook (desktop).
• The problem is simple but critical—I cannot open the OST at all; Outlook stops with an error each time.
• I already attempted the usual ScanOST/ScanPST utilities and a couple of demo recovery tools, but nothing produced a usable result.

What I need from you
1. Diagnose the corruption and recover the full mailbox data.
2. Supply a working file I can open directly in Outlook, or a clean PST/OST export containing every item intact and de-duplicated.
3. Provide a brief outline of what you did so I can understand the steps in case this happens again.

Acceptance criteria
• The repaired file loads in my current version of Outlook with no error messages.
• All folders, messages, attachments, calendar items, tasks, and contacts are present and readable.
• No duplicates, missing items, or obvious corruption artifacts.

If additional information is required—file size, Outlook build, server type—let me know right away and I’ll provide it. I’m ready to share the file via a secure transfer method as soon as we agree on the approach.