⚠️ 3 verified solutions available for Error 805 — Last updated 2026-03-17
Error 805 📋

Fix ERROR_INVALID_ACE_CONDITION — Windows Error Code 805

Error 805 (ERROR_INVALID_ACE_CONDITION) is a Windows File & Disk error that occurs when the specified access control entry (ace) contains an invalid condition.. This guide provides step-by-step solutions to resolve this issue.

🏷️ Code: 805 📛 ERROR_INVALID_ACE_CONDITION 📅 Updated: 2026-03-17 ⏱️ 3 Solutions
⚡ Quick Fix

Check and Repair Disk Errors: Open Command Prompt as Administrator

👇 See all 3 solutions below
🐞 Auto-Fix Script for Error 805
⚠️ How to use: Open PowerShell as Administrator, paste the code above, and press Enter.
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📑 Table of Contents
What is Error 805? Common Causes Step-by-Step Solutions Prevention Tips Related Errors

💡 What is Error 805?

Windows System Error Code 805, known as ERROR_INVALID_ACE_CONDITION, is a File & Disk error that occurs during file system and disk I/O operations. The error indicates that: The specified access control entry (ACE) contains an invalid condition. When this error is encountered, the Windows operating system was unable to complete the requested operation within the file management subsystem. The error code 805 is returned by the GetLastError() function and provides developers with a specific identifier to diagnose the root cause of the failure. The symbolic name ERROR_INVALID_ACE_CONDITION maps directly to this numeric code and is commonly referenced in Microsoft documentation, developer forums, and system logs. Understanding this error and its context within file system and disk I/O operations is essential for effective troubleshooting.

⚠️ Common Causes

  • System resource conflict: The specified access control entry (ACE) contains an invalid condition.
  • The file or directory does not exist or was moved
  • Insufficient permissions on the target
  • Disk has bad sectors or is full
📚 Comprehensive Guide

The Definitive Guide to Missing DLL Errors and Safe Restoration

An encyclopedic guide on understanding Dynamic Link Libraries, diagnosing 'DLL is missing' errors, reading dependencies, and safe restoration methods.

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✅ Step-by-Step Solutions

1 Check and Repair Disk Errors
  1. Open Command Prompt as Administrator
  2. Run: chkdsk C: /f /r (replace C: with affected drive)
  3. Type Y to schedule scan on next restart
  4. Restart and wait for the scan to complete
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2 Verify File Permissions
  1. Right-click the file/folder → Properties → Security tab
  2. Click Edit → Add your username → Grant Full Control
  3. Click Apply → OK
3 Use Windows File Recovery
  1. If a file was accidentally deleted, check Recycle Bin first
  2. Install 'Windows File Recovery' from the Microsoft Store (free)
  3. Run: winfr C: D: /extensive (scans C:, saves to D:)
  4. Check the recovered files in the output folder

🎬 Video Tutorials

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How to fix Error 805 (Invalid Ace Condition)
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💻 Diagnostic Command

Run this PowerShell command to find related events in your system log:

Get-EventLog -LogName System -Newest 20 | Where-Object {$_.Message -like "*805*" -or $_.Message -like "*ERROR_INVALID_ACE_CONDITION*"} | Format-List

💡 Open PowerShell as Administrator, paste the command above, and press Enter.

🛡️ Prevention Tips

  • Back up important files regularly
  • Run CHKDSK periodically
  • Keep 15%+ free space on system drive
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Last updated: 2026-03-17
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Based on Official Microsoft Documentation
Solutions Tested on Windows 10 & 11
Error codes sourced from Microsoft Win32 SDK. Updated 2026-03-17.
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