admin.microsoft.com doesn’t support a secure connection with HTTPS

Question

Answer 1

Dear @Rajesh Bhandari,

Thank you for posting your question in the Microsoft Q&A forum.

Based on description in screenshot, you’re seeing “admin.microsoft.com doesn’t support a secure connection because the browser cannot establish an HTTPS connection with the Microsoft 365 Admin Center. This usually points to SSL/TLS or network configuration issues rather than the site being insecure.

Here are some suggestions you can try:

The message says you are in InPrivate mode. Try opening the site in a normal browser window. Some extensions or policies block HTTPS in private sessions.

Verify TLS Settings

• Press Win + R, type inetcpl.cpl, go to Advanced tab.
• Ensure Use TLS 1.2 and Use TLS 1.3 are checked. Apply and restart.

Clear Browser Cache & Cookies

• Outdated cache can interfere with SSL validation.

Disable SSL Inspection in Antivirus

• Temporarily turn off SSL scanning in your antivirus/firewall.

Check Network Configuration

• Remove VPN or proxy temporarily.
• Ensure Microsoft 365 endpoints (*.cloud.microsoft.com, *.office.com) are allowed

For more detail information, here are some articles you can refer to:

Reviewing network connection failures for your tenant users when they connect to Microsoft 365 services

Step 3: Secure and configure your network

Besides that, you can refer this Microsoft 365 Administration troubleshooting

Kindly noted that

Make sure you are using:

https://admin.microsoft.com

If you typed http:// or clicked an insecure link, it will trigger this error.

I hope information above helpful, if you have any other questions, please feel free to reach out.

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