| Issue | Primary Cause | Recommended Fix |
|---|---|---|
| PowerPoint Login Failed | Corrupt Identity Cache | Clear Windows Credentials |
| Repeated Credential Prompts | Expired Token / MFA Conflict | Sign out of all Office Apps |
| Activation Error | Outdated Office Version | Run Microsoft Support and Recovery Assistant |
What is PowerPoint Credentials Not Working?
The “PowerPoint credentials not working” error occurs when the application fails to authenticate your Microsoft 365 account. Even if you enter the correct username and password, the system may repeatedly prompt for login or show a “Login Failed” message.
This issue typically stems from a synchronization mismatch between your local machine and the Microsoft Azure Active Directory. It can also be caused by corrupted identity folders or cached tokens in the Windows Credential Manager.
In many cases, this prevents users from saving files to OneDrive, collaborating in real-time, or accessing premium templates. Understanding that this is a local caching issue rather than an account lockout is the first step to a fix.
Step-by-Step Solutions
1. Clear Office Credentials from Windows
The most effective way to resolve this is to manually remove the stored login tokens that are causing the conflict.
Close all Microsoft Office applications. Open the Control Panel and navigate to User Accounts > Credential Manager. Select Windows Credentials.
Look for any entries containing “MicrosoftOffice16” or “SSO_Pop_Device.” Expand them and click Remove. You can also trigger the credential manager interface via the command line:
control keymgr.dll2. Sign Out and Remove Account in Windows Settings
Sometimes the operating system “remembers” a broken session. Go to your Windows Settings > Accounts > Access work or school.
Find the account associated with the PowerPoint error. Click Disconnect. Note that this won’t delete your data; it simply severs the authentication bridge. Restart PowerPoint and sign in again.
3. Repair the Microsoft 365 Installation
If the login module itself is corrupted, a quick repair can restore the necessary DLL files. This does not affect your PowerPoint files.
Go to Settings > Apps > Installed Apps. Find Microsoft 365, click the three dots, and select Modify. Choose Online Repair for the most thorough fix.
4. Delete the Identity Registry Key
If the issue persists, you may need to force PowerPoint to recreate its identity cache. Use this method with caution as it involves the Registry Editor.
Navigate to the following path in the Registry Editor and delete the “Identity” folder:
HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\IdentityAfter deleting this key, restart your computer. When you launch PowerPoint, it will treat the session as a fresh login, bypassing the previous “Login Failed” loop.