PST File Processing Failed - Troubleshooting Guide

When uploading a PST file to RedactBox, the file shows as "Failed" with the message:

Written By Harry Elliott

Last updated About 8 hours ago

Problem

When uploading a PST file to RedactBox, the file shows as "Failed" with the message:

"This file could not be processed. It may be too large or corrupt."

Cause

This error typically indicates that your PST file has internal corruption. PST files use a complex B-tree index structure to store emails, folders, and attachments. When this structure becomes damaged, email extraction tools cannot read the file properly.

Common Causes of PST Corruption

  • File size exceeded limits - Older versions of Outlook had a 2GB limit for PST files

  • Unexpected shutdown - Outlook closing unexpectedly during file operations

  • Storage issues - Hard drive errors, bad sectors, or network interruptions

  • Incomplete transfers - File not fully downloaded or copied

  • Software conflicts - Antivirus or backup software interfering with Outlook

Solution

Step 1: Run Microsoft's Inbox Repair Tool (ScanPST.exe)

Microsoft includes a free repair tool with Outlook called ScanPST.exe. This tool can fix many common PST corruption issues.

Locate ScanPST.exe on your computer:

Outlook VersionDefault Location

Outlook 365/2021/2019

C:\Program Files\Microsoft Office\root\Office16\SCANPST.EXE

Outlook 2016

C:\Program Files\Microsoft Office\Office16\SCANPST.EXE

Outlook 2013

C:\Program Files\Microsoft Office\Office15\SCANPST.EXE

Outlook 2010

C:\Program Files\Microsoft Office\Office14\SCANPST.EXE

Note: If you have 32-bit Office on 64-bit Windows, check C:\Program Files (x86)\... instead.

Run the repair:

  1. Close Outlook completely (check Task Manager to ensure it's not running)

  2. Navigate to the ScanPST.exe location and double-click to run it

  3. Browse to select your corrupted PST file

  4. Click "Start" to begin scanning

  5. If errors are found, click "Repair"

  6. Repeat steps 4-5 until no more errors are found (may take several passes)

Step 2: Re-upload to RedactBox

After repairing the PST file:

  1. Delete the failed file from your RedactBox project (click the trash icon)

  2. Upload the repaired PST file again

Still Having Issues?

If ScanPST.exe doesn't resolve the problem:

  • Try a third-party repair tool - Tools like Stellar Repair for Outlook or Kernel for Outlook PST Repair can handle more severe corruption

  • Export to a new PST - Open the damaged PST in Outlook, then export emails to a new PST file

  • Contact support - Reach out to us with details about your file and we'll help investigate

Prevention Tips

To avoid PST corruption in the future:

  • Keep PST files under 10GB when possible

  • Store PST files on local drives, not network locations

  • Ensure Outlook closes properly before shutting down

  • Regularly back up important PST files

  • Consider using Outlook's OST/cached mode instead of PST files