Outlook Login Error

Question

Correlation Id: [Moderator note: Personally Identifiable Information removed]

Timestamp: 2026-08-03T13:47:43.000Z

DPTI: [Moderator note: Personally Identifiable Information removed]

Message: An unexpected error occurred.

Tag: 7ita9

Code: 3399811147

Answer 1

Hi Wesley,

Thank you for posting your question to Microsoft Q&A Forum.

Error code 3399811147, often accompanied by the message “Something went wrong. [7ita9]”, disrupts sign-in for Office 365 or work/school accounts on the desktop version of Office. This error typically appears after changes to account credentials, device migrations, or when cached authentication data becomes corrupted. While access to Office on the web usually remains available, the desktop application fails to authenticate, blocking productivity.

Option 1: Repair Windows Account Manager (WAM) authentication

Step 1: Open the Windows search bar, type PowerShell, right-click on Windows PowerShell, and select “Run as administrator.” This step is essential because administrative rights are required to register system components.

Step 2: In the PowerShell window, enter the following commands one at a time, pressing Enter after each. These commands re-register key Windows components responsible for account authentication:

Add-AppxPackage -Register "$env:windir\SystemApps\Microsoft.AAD.BrokerPlugin_cw5n1h2txyewy\Appxmanifest.xml" -DisableDevelopmentMode -ForceApplicationShutdown
Add-AppxPackage -Register "$env:windir\SystemApps\Microsoft.Windows.CloudExperienceHost_cw5n1h2txyewy\Appxmanifest.xml" -DisableDevelopmentMode -ForceApplicationShutdown

Step 3: Close PowerShell and restart your computer. This ensures all authentication services reload with the repaired configuration.

Option 2: Remove and re-add Work or School account

Step 1: Click on the Windows Start menu and select Settings. Navigate to Accounts and then Access work or school.

Step 2: Locate your connected work or school account. Click on it and select Disconnect. Confirm any prompts to remove the account from your device. This step clears conflicting or outdated account tokens that can prevent successful authentication.

Step 3: Restart your computer to clear any lingering session data.

Step 4: Return to Access work or school in Settings, then select Connect. Enter your credentials to re-add your account. This process initiates a fresh authentication handshake with Microsoft’s servers.

Option 3: Clear Cached Credentials in Windows Credential Manager

Step 1: Open the Windows search bar and type Credential Manager. Select the Credential Manager control panel entry.

Step 2: Click on Windows Credentials, then review the list for any entries related to MicrosoftOffice, or Office365. Click each and select Remove to delete them. This clears out expired or corrupted authentication tokens that block successful sign-in.

Download OLicenseCleanup.vbs and run it. In this way, you can use this package to remove license, remove cached identities in HKCU registry and remove credentials. For more details, you can refer to this article: Reset Microsoft 365 Apps for enterprise activation state. 

Reboot your device. 

Reopen Office apps and sign in with the correct account. 

I hope this information is helpful. Please follow these steps and let me know if it works for you. If you have any updates regarding the issue, please feel free to share them with me.   

Thank you for your patience and your understanding. If you have any questions or need further assistance, please feel free to share them in the comments on this post so I can continue to support you.   

I look forward to continuing the conversation.   

---

If the answer is helpful, please click "Yes" and kindly upvote it. If you have extra questions about this answer, please click "Comment".      

Note: Please follow the steps in the forum documentation to enable e-mail notifications if you want to receive the related email notification for this thread.