TooManyObjectsOpenedError Windows PC

Dear @Scarlett Sahota,

Thank you for reaching out to Microsoft Q&A forum.

I’m really sorry to hear about the trouble you’re having signing in to your Outlook account. I know how frustrating it can be when your email just won’t load, especially if you rely on it for work or personal communication. Based on the details you’ve shared, your mailbox appears to have exceeded the maximum number of active server “handles” (connections) allowed by Exchange. The TooManyObjectsOpenedException typically occurs when background sessions such as those from mobile devices, web browsers, or third-party integrations remain open for too long, preventing new sessions from being established.

As a forum moderator, I genuinely wish I could directly access your account or delve into the backend systems to diagnose and fix this for you. However, our role here is limited to providing general guidance and solutions that can be applied by users.  

From my research, this issue is often related to hitting a MAPI object limit, which can occur when a mailbox is structured in certain ways.

• Ensure your mailbox contains fewer than 500 total folders, including subfolders. A high folder count is one of the most common causes of this exception.
• If you have multiple shared mailboxes or delegated accounts added to your Outlook sidebar, try removing them temporarily. Each one consumes multiple server objects.
• Since you’ve already tried clearing cache and cookies without success, the issue is likely caused by sessions stuck on the server side rather than your local device.

Please follow these steps. This process is different from simply signing out of your browser, it sends a command to Microsoft servers to terminate all active sessions:

1. Go to your Microsoft Account Security page.
2. Scroll down to the bottom and find the section "Lost device".
3. Click Sign out everywhere.
4. Important: You must now wait at least 30–60 minutes without trying to log back in. This allows the Exchange server to "garbage collect" the stuck object handles.

Additionally, your error log indicates esrc: StartupData and BootResult: throttle, which suggests Outlook is failing during the initial folder-loading process. You may be able to bypass this by using the following alternative URL:

• Try logging in via this alternative URL: https:// outlook.com/mail/?n=1
• The ?n=1 parameter forces Outlook to ignore your cached session data and load a fresh instance.

If none of the steps above resolve the issue, I recommend contacting your IT administrator. They can run server-side repair commands such as a mailbox repair using Exchange PowerShell to resolve the problem.

For reference: New-MailboxRepairRequest (ExchangePowerShell) | Microsoft Learn

I hope this information helps clarify the situation and provides you with workable solutions. Should you have any further questions or need additional assistance, please don't hesitate to reach out. We're always here to help. Have a wonderful day! 

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