Suddenly Outlook on Samsung S26 Ultra stopped working

Based on similar Outlook for Android issues on Samsung devices, the most effective fix is a full remove/reinstall of Outlook and any related Microsoft apps, then setting it up again cleanly.

Follow these steps on the Samsung S26 Ultra:

1. Uninstall Outlook and Teams (if installed)
   • Go to Android Settings → Apps.
   • Find Microsoft Outlook and Microsoft Teams.
   • Tap each app → Uninstall.
2. Clear any remaining app data (if options remain)
   • In Settings → Apps → Outlook (if still listed), tap Storage → Clear cache and Clear data.
3. Reboot the phone
   • Power the device off completely, wait a few seconds, then power it back on.
4. Reinstall Outlook
   • Install Outlook for Android again from the store.
5. Set up the account again
   • Open Outlook and add the email account.
   • If prompted to configure the account as IMAP or POP, cancel and instead configure it using Exchange/Exchange ActiveSync or the default Microsoft 365/Outlook.com option, because IMAP/POP cannot sync calendar and contacts.
6. If calendar/contacts still do not sync
   • In Outlook for Android, go to Settings → [the affected account] → Reset Account.
   • If that fails, Delete Account → Delete From This Device, then add the account again.

If the account is a Microsoft 365 work/school account and problems persist after these steps, contact the Microsoft 365 admin or technical support for the organization. For Outlook.com addresses (hotmail.com, live.com, etc.) that previously synced and now do not, use the Outlook.com sync troubleshooting guidance referenced below.

References:

• Troubleshoot Outlook mobile issues
• Set up email in the Outlook for Android app
• Can't sync calendar and contacts with my phone or tablet

Hi Paul M Johnson,

Welcome to Microsoft Q&A forum. 

I can see that the Q&A Assist answer already covered the core steps (uninstall, clear cache/data, restart, reinstall, then set up the account again). I would like to add one more step that often helps on some Samsung devices when Outlook or Teams shows a black screen or gets stuck loading, and it relates to Android System WebView.

1. Refresh Android System WebView

• Open Settings and search for Android System WebView.
• Open its page in Google Play, then select Remove updates.
• Restart the phone.
• Go back to Google Play and update Android System WebView to the latest version.
• Update Google Chrome as well, then restart the phone one more time.

2. Then repeat the Q&A Assist steps

• Uninstall Outlook (and Teams if installed), restart the phone, then reinstall Outlook from the Play Store.
• Sign in again.
• If mail or calendar still does not sync, go to Outlook Settings, select the account, then choose Reset Account.

Please feel free to let me know if you have any further updates, thanks.

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This solved my problem: https://learn.microsoft.com/en-us/answers/questions/5862178/my-microsoft-apps-have-stopped-working-on-my-samsu