Clients using Microsoft 365 Business Basic may sometimes encounter an error while accessing Outlook on the Web (OWA) that displays the message:
Something went wrong
We are sorry, but an error occurred. Please try again later.
This article explains what the error means and how it can be resolved.
What Does This Error Mean?
The diagnostic message usually shows:
- Application: Mail
- Error Source: IndexPageIncomplete
This indicates that Outlook Web was able to authenticate the user successfully, but failed to fully load the mailbox interface. It is a session or UI loading issue, not a mailbox deletion or subscription expiry problem.
Common Causes
- Corrupted browser cache or cookies
- Browser extensions (ad blockers, privacy tools, antivirus plugins)
- Temporary Microsoft 365 backend issues
- Session token mismatch after password or license changes
- Network, DNS, or ISP-level filtering
Recommended Troubleshooting Steps
1. Open Outlook in Incognito / Private Mode
Access https://outlook.office.com in an incognito window and sign in. If it works, the issue is browser-related.
2. Clear Outlook-Related Cookies
Clear cookies for the following domains and reload the browser:
- outlook.office.com
- office.com
- microsoftonline.com
3. Disable Browser Extensions
Temporarily disable ad blockers, script blockers, and antivirus web extensions, then reload Outlook Web.
4. Try a Different Browser
Microsoft Edge is recommended for Microsoft 365 services. Testing in another browser helps identify profile-specific issues.
5. Use Direct Mail URL
Access the mailbox directly using:
https://outlook.office.com/mail/
Administrator Checks
Microsoft 365 administrators should verify the following:
- Business Basic license is assigned correctly
- Exchange Online service is enabled
- User mailbox is active and not in provisioning state
- No recent license removal or reassignment (allow 15–30 minutes after changes)
Temporary Workarounds
- Use the Outlook mobile application
- Configure the account in a third-party email client using IMAP
These options remain fully supported under Microsoft 365 Business Basic.
When to Contact Microsoft Support
If the issue persists, Microsoft Support may need to reset the mailbox web session. Provide them with:
- Error source: IndexPageIncomplete
- Timestamp shown in the error
- Client IP address from diagnostic details
- A screenshot of the error page
Key Takeaways
- This is not a data loss issue
- This is not a subscription expiry issue
- The problem is usually temporary and fully recoverable
Systron.net assists clients with Microsoft 365 troubleshooting, administration, and support to ensure uninterrupted business communication.
