Troubleshoot the Microsoft 365 "Something Went Wrong" 500 Error

After the Microsoft Office 365 service migration to Ingram Micro, some users may encounter a "Something went wrong" (500 Error) message when accessing Outlook on the web.

This issue may occur when Microsoft 365 successfully signs in the user but cannot open the mailbox because the required Exchange Online license is missing, disabled, or the mailbox has not yet been provisioned.

Symptoms

Users attempting to access Outlook on the web may encounter the following error:

Outlook on the web: "Something went wrong" (500 Error)

Common Causes

This issue may occur when:

• No Exchange Online license is assigned to the user.
• A license was recently assigned, and mailbox provisioning is still in progress.
• An Exchange Online license is assigned, but the Exchange Online service is disabled.
• Mailbox creation has not completed successfully after migration.

Troubleshoot the 500 Error After Microsoft 365 Migration

Before You Begin

To complete the steps in this article, you must:

• Have administrator access to the Microsoft 365 Admin Center.
• Have administrator access to the Exchange Admin Center.
• Know the email address of the affected user.

Step 1: Verify the Exchange Online License

1. Sign in to the Microsoft 365 Admin Center.
2. In the left navigation menu, select Users.
3. Click Active users.
4. Select the affected user.
5. Open Licenses and apps.
6. Confirm the following:
   • A license that includes Exchange Online is assigned.
   • The Exchange Online service toggle is enabled.

     
      

Step 2: Confirm the Mailbox Exists

1. Sign in to the Exchange Admin Center.
2. Select Recipients.
3. Click Mailboxes.
4. Search for the affected user.
5. Verify that the user's mailbox appears in the mailbox list.

   
    

Step 3: Allow Time for Mailbox Provisioning

If a license was recently assigned:

1. Wait for mailbox provisioning to complete.
2. Sign out of Outlook on the web.
3. Close all browser windows.
4. Sign back in and test access again.

Once mailbox provisioning is complete and the Exchange Online service is enabled, Outlook on the web should open normally.

Frequently Asked Questions

Summary

The "Something went wrong" (500 Error) may occur after the Microsoft Office 365 service migration to Ingram Micro when Outlook on the web cannot access the user's mailbox. This is typically caused by a missing or disabled Exchange Online license, incomplete mailbox provisioning, or the absence of an Exchange mailbox. By verifying the user's license assignment, confirming that Exchange Online is enabled, and ensuring that the mailbox exists and has been fully provisioned, you can often resolve the issue and restore access to Outlook on the web.