Unreadable PDF? How to Diagnose and Repair a Corrupted File

The error 'This file is corrupt or damaged' is a professional's nightmare. It often occurs after an incomplete download or a disk write error. **Diagnosis**: If the file is 0 KB, it's irrecoverable. If it has a normal weight but doesn't open, the internal structure (XREF table) is probably broken. **Reconstruction Technique**: Our repair tool uses `qpdf` to scan the document's object tree. It attempts to rebuild the page index and close open data streams. **Last Resort (OCR)**: If the structure is too damaged, we try to extract pages as high-definition images, then run an optical character recognition (OCR) engine to recreate a healthy document. This is often the only way to recover text from a corrupted contract.