I faced the same issue when I couldn’t access my OST files after an Exchange crash. I used BitRecover OST Converter, and it worked perfectly. Here’s what I did:
Installed and launched the software on my PC.
Added my inaccessible OST files using the Select Files option.
The software automatically scanned and displayed all my mailbox items.
I previewed my emails and attachments to check the data.
Selected PST as the output format and chose a saving location.
Finally, clicked on Convert, and within minutes, I had all my emails restored in PST format.
It was quick, secure, and I didn’t lose any data during the conversion.