How to Fix Outlook Stuck in Sign-In Loop (12 Working Fixes)

Outlook getting stuck in a sign-in loop is a common issue where the app keeps asking for credentials without ever completing login, even after entering the correct password. This affects classic Outlook, the new Outlook app, and Outlook on the Web, and it usually comes down to a handful of authentication, cache, profile, or app component related causes.

What Causes Outlook Sign-In Loop

• Corrupted or outdated cached credentials and OAuth tokens
• A corrupted local Outlook profile or damaged new Outlook app package
• Incorrect system date, time, or time zone breaking token validation
• A stale work/school account connection or an outdated WebView2/Office installation

Fix 1: Clear Cached Credentials

Old or mismatched credentials in Windows Credential Manager are one of the most common triggers for this loop, since Outlook keeps trying to authenticate with stale tokens instead of prompting a clean login.

1. Close Outlook completely, including background processes in Task Manager.
2. Open Control Panel and go to Credential Manager.
3. Click Windows Credentials, then look for entries starting with MicrosoftOffice16_Data, MicrosoftAccount, or your email address.
4. Select each related entry and click Remove.
5. Restart Outlook and sign in again from scratch.

Fix 2: Fix Date, Time, and Time Zone Sync

Modern Authentication relies on OAuth tokens that are time sensitive, so a system clock that has drifted out of sync can cause every sign-in attempt to silently fail and loop back.

1. Right-click the clock in the taskbar and select Adjust date/time.
2. Turn on Set time automatically and Set time zone automatically.
3. Click Sync now under Additional clock settings if available.
4. Restart the computer and try signing into Outlook again.

Fix 3: Check Authentication Settings in Classic Outlook

Classic Outlook has a Security setting that can force repeated credential prompts on every connection attempt if it gets enabled unintentionally.

1. In Outlook, go to File > Account Settings > Account Settings.
2. Select your account under the Email tab and click Change.
3. Click More Settings, then open the Security tab.
4. Make sure Always prompt for login credentials is unchecked, then click Apply.

Fix 4: Sign Out Everywhere from Account Security Settings

Sometimes an active session token elsewhere keeps colliding with the sign-in attempt, and forcing a global sign-out clears every stale session at once instead of just the local cache.

1. Go to the Microsoft account Advanced security options page in a browser.
2. Select Sign out everywhere to sign out of all browsers and apps tied to the account.
3. Allow up to 24 hours for the change to fully take effect.
4. Reopen Outlook and sign in again with your credentials.

Fix 5: Clear Browser Cache and Cookies for Outlook on the Web

Since Outlook on the Web runs entirely in the browser, a corrupted cache or stale cookies can cause the same sign-in loop even though no desktop app is involved.

1. Press Ctrl + Shift + Delete in your browser to open the clear browsing data window.
2. Select the Cache and Cookies checkboxes.
3. Click Clear, then restart the browser.
4. Go to Outlook on the Web and try signing in again.

Fix 6: Reset the Office Identity Cache

Outlook stores an identity cache separate from Credential Manager, and a corrupted cache here can cause the app to bounce back to the login screen even after credentials are cleared.

1. Close Outlook and any other Office apps.
2. Press Win + R, type %localappdata%\Microsoft\Office\16.0\Wef, and delete the contents of this folder if it exists.
3. Press Win + R again, type %localappdata%\Microsoft\IdentityCache, and delete the folder.
4. Reopen Outlook and let it recreate the identity cache during a fresh sign-in.

Fix 7: Update the WebView2 Runtime

The new Outlook app renders its sign-in screen using the Microsoft Edge WebView2 Runtime, so an outdated or missing WebView2 component can break the sign-in flow and trigger the loop.

1. Open Microsoft Edge and let it install any pending updates, since Edge updates typically update WebView2 as well.
2. Alternatively, download the latest WebView2 Runtime installer directly from Microsoft.
3. Restart the computer after the update completes.
4. Reopen the new Outlook app and try signing in again.

Fix 8: Disconnect and Reconnect the Work Account in Windows Settings

If the account is connected oddly at the Windows level, it can interfere with Microsoft 365 desktop sign-in independently of anything inside Outlook itself.

1. Open Settings and go to Accounts > Access work or school.
2. Select the connected account tied to the looping Outlook profile.
3. Click Disconnect, then restart the PC.
4. Reconnect the account and reopen Outlook to test sign-in.

Fix 9: Create a New Outlook Profile

A corrupted local profile can hold broken authentication metadata that keeps forcing Outlook back into the loop even after the cache and credentials are cleared.

1. Close Outlook, then open Control Panel and search for Mail.
2. Click Mail (Microsoft Outlook), then select Show Profiles.
3. Click Add, name the new profile, and enter your email and password to set it up.
4. Set the new profile as the default under Always use this profile, then open Outlook and test sign-in.

Fix 10: Repair or Reset the New Outlook App

The new Outlook app is packaged separately from classic Outlook, so its own local app data can get corrupted even when Credential Manager and the identity cache are already clean.

1. Open Settings and go to Apps > Installed apps.
2. Find Outlook (new), click the … menu next to it, and select Advanced options.
3. Select Repair first and test sign-in.
4. If the loop continues, go back and select Reset, which clears local app data and forces a fresh sign-in.

Fix 11: Repair or Reinstall Microsoft Office

Corrupted Office installation files can interfere with how Outlook validates authentication, independent of any cache or profile issue.

1. Open Control Panel > Programs and Features, locate Microsoft Office or Microsoft 365, and select Change.
2. Choose Quick Repair first and let it complete.
3. If the loop persists, run the same repair again and choose Online Repair instead, which replaces damaged files from Microsoft’s servers.
4. Restart the computer and open Outlook to test sign-in.

Fix 12: Uninstall and Reinstall the New Outlook App

If none of the repair steps resolve the loop, a full reinstall gives the new Outlook app a completely clean set of local files to work with.

1. Right-click the Start menu, go to Installed apps, and find Outlook (new).
2. Select Uninstall and confirm.
3. Restart the computer, then open the Microsoft Store and reinstall the new Outlook app.
4. Sign in again once the fresh install completes.

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