Microsoft 365 Error Codes

Fix Microsoft 365 Login Error 0x8004de44 and Error 29

Guest Writer Sep 28, 2026 869 views

Question details

The user is experiencing unexpected sign-outs, login window crashes, and errors 0x8004de44 or Error 29 when trying to activate or use Microsoft 365 apps.

How to Fix Microsoft 365 Login Error 0x8004de44 and License Update Errors

Product: Microsoft 365
Device & OS: Windows
Scenario: Activating or logging into a Microsoft 365 subscription on a PC or a newly set up laptop.
Observed behavior: The login window closes immediately without completing the process, apps sign out unexpectedly, and errors such as 0x8004de44, Error 29, or "Couldn't update license" are displayed despite having a valid subscription.

Before you start

Ensure your Microsoft 365 subscription is currently active and verify that you have administrator privileges on your computer, as you will need to modify system files and the Windows Registry.

Solution 1Recommended

Clear Office Identity Cache and Reset Authentication Registry Key

Deleting corrupted authentication data from the local app data folders and registry is the most effective way to resolve persistent Microsoft 365 login and license errors.

Microsoft 365 stores login tokens and identity data locally. When this data becomes corrupted, the login window may crash or fail to connect to activation servers, resulting in Error 0x8004de44 or Error 29.

Clear Local Authentication Folders

Press Win + R to open the Run dialog. Type %localappdata%\Microsoft and press Enter. Locate the folders named 'OneAuth' and 'IdentityCache'. Delete all contents inside both of these folders.

Open Registry Editor

Press Win + R again, type 'regedit' in the Run dialog, and press Enter to open the Windows Registry Editor. Click 'Yes' if prompted by User Account Control.

Delete the Office Identity Key

Navigate to the following path: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Common\Identity. Right-click the 'Identity' folder, select 'Export' to create a backup on your Desktop, and then right-click it again and select 'Delete'.

Restart and Sign In

Restart your computer completely. Open Microsoft Word or Excel and attempt to sign in to your Microsoft 365 account again.

Clear Office Identity Cache and Reset Authentication Registry Key

Registry Editing Caution: Editing the Windows Registry can affect system stability. Always export a backup of the registry key (as described in the steps) before deleting it.

Solution 2

Start Windows with a Clean Boot

A clean boot disables non-essential startup software and background services to help identify if third-party apps (like antivirus or firewalls) are interfering with the Office login process.

Solution 3

Reinstall Microsoft 365 with the Offline Installer

If clearing the cache and performing a clean boot fail, the installation files might be deeply corrupted. Using the offline installer bypasses potential network interruptions during setup.

Free Microsoft Office alternative

Try WPS Office - A Free, Lightweight Alternative to Microsoft 365

If Microsoft 365 activation issues, recurring Error 29, and login crashes continue to disrupt your workflow, consider switching to WPS Office. It provides robust tools for editing Word, Excel, and PowerPoint files without the hassle of complex subscription validations or registry errors.

1. Download WPS Office: Visit the official WPS website and download the free installer for your operating system.
2. Install the Software: Run the installer and follow the quick setup instructions. No complicated account or registry configurations are required to start working.
3. Open Your Documents: Launch WPS Office and open your existing Word, Excel, or PowerPoint files to continue your work without missing a beat.

Fully compatible with Microsoft Office formats including DOCX, XLSX, and PPTX.Completely free to download and use with a familiar, easy-to-learn user interface.Lightweight installation that avoids complex registry dependencies and login crashes.All-in-one suite to manage documents, spreadsheets, and presentations seamlessly.

microsoft office alternative - wps office

Frequently Asked Questions

Why does the Microsoft 365 login window close immediately?

This usually happens when the locally cached authentication tokens (stored in the OneAuth and IdentityCache folders) become corrupted or conflict with existing registry keys, which forces the app to abruptly terminate the login sequence.

What does Microsoft 365 Error 29 mean?

Error 29 is a licensing and activation error indicating that Microsoft 365 is unable to verify your subscription status. This is often caused by corrupted local identity data, network interference, or a breakdown in communication with Microsoft's activation servers.

Will deleting the Office Identity registry key cause data loss?

No. Deleting the Identity registry key only clears your sign-in profiles and temporary authentication preferences. Your personal documents, emails, and files stored locally or on OneDrive remain perfectly safe.

How do I backup the IdentityCache folder before deleting it?

Navigate to %localappdata%\Microsoft\ using the Windows Run dialog. Locate the IdentityCache folder, right-click it, select 'Copy', and then 'Paste' it onto your Desktop or another safe location before deleting the original folder.

Microsoft Office Error Codes