Updated from Essentials to Business and now can't log in

Dear @Nikki, 

I understand you’ve upgraded from Essentials to a Business plan and can access Outlook on the web, but you’re unable to sign in to the desktop app. 

Since the exact Business plan wasn’t mentioned, here’s some clarification: 

• Microsoft 365 Business Basic: Web and mobile apps only (desktop apps not included). 
• Microsoft 365 Business Standard and Business Premium: Full access to web, mobile, and desktop apps. 

Please verify which Business plan is currently tied to your account: 

• If it’s Business Basic, desktop app access isn’t supported. Based on your needs, you may want to consider upgrading to Business Standard or Business Premium. 

You can find more detailed information about Business plans in the following resources: 

Microsoft 365 Business Plans and Pricing | Microsoft 365 

Microsoft 365 Business Standard | Microsoft 365 

Microsoft 365 Business Premium | Microsoft 365 

• If you already have Business Standard or Business Premium: 

The issue may be related to license propagation or sync delays. These changes can take up to 24 hours to fully replicate across services like Exchange Online.  

Additional information is available in the following resource: Delays in provisioning a user or mailbox - Exchange | Microsoft Learn 

You’re currently at 22 hours, so it may resolve shortly, but here are steps you can try in the meantime: 

Option 1: Repair or recreate Outlook Profile 

Close Outlook. 

Go to Control Panel > Search for “Mail” and select it > Show Profiles. 

Create a new profile and set it as default. 

Restart Outlook and sign in again. 

Option 2: Clear Outlook cache 

Close the Outlook app completely.  

Open the Run dialog by pressing Windows + R.  

Type or paste the following command and click OK:  

olk.exe --devtools  

The new Outlook will open (you may need to sign in), and the DevTools window will appear.  

In DevTools:   

Click Application on the toolbar.  

Clear local storage cache: Under Storage, find https://outlook.office.com, under Local Storage, right-click it, and select Clear.  

Clear cookies: Under Cookies, locate https://outlook.office.com., right-click it, and select Clear.  

Close the DevTools window.  

Once completed, the cache for the new Outlook will be cleared. Please note that this process removes temporary files, including saved login credentials, so you may need to sign in again. 

Option 3: Clear cached credentials 

Open the Control Panel on your PC.    

Go to User Accounts > Credential Manager.    

Under both Windows Credentials and Generic Credentials, look for any entries related to your Microsoft 365 account.    

Select and remove those entries.    

Restart your computer and try adding your account to Outlook again.    

Option 4: Contact Microsoft Support 

If the issue persists after these steps, please reach out to your IT administrator to contact Microsoft Support for further assistance. 

A technical support engineer can perform a remote session to investigate the situation, verify the backend configurations, and run any necessary synchronization tools to resolve the problem. If the issue requires further attention, they can escalate it to a specialized team for deeper analysis.  

• I sincerely recommend reaching out to your IT administrator to create a support ticket via Microsoft Admin Center > Support > Help & Support for further investigation.  

• Microsoft provides customer service phone numbers based on your region. You can find the appropriate contact number here: Customer service phone numbers - Microsoft Support 

As community moderators, we kindly ask for your understanding that our access to internal development details is limited. Our primary role is to guide users toward the appropriate resources and support channels. While we may not have visibility into performing deeper backend analysis, we’ll continue doing our best to support you within the scope of our responsibilities.  

I hope this information is helpful. Please follow these steps and let me know if it works for you. If not, we can work together to resolve this.    

Thank you for your patience and understanding. If you have any questions or need further assistance, please feel free to share them in the comments on this post so I can continue to support you. 

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