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This Connection is Untrusted - mail.live.com - sec_error_unknown_issuer

  • 5 replies
  • 35 have this problem
  • 1 view
  • Last reply by ff1523

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I've been getting this issue with outlook.com or mail.live.com when I try to access my email through FireFox.


Below is the full error: This Connection is Untrusted You have asked Firefox to connect securely to dub120.mail.live.com, but we can't confirm that your connection is secure.

Normally, when you try to connect securely, sites will present trusted identification to prove that you are going to the right place. However, this site's identity can't be verified.

dub120.mail.live.com uses an invalid security certificate. The certificate is not trusted because no issuer chain was provided. (Error code: sec_error_unknown_issuer)


I've been trying to access this site for a while using FireFox but I have had no luck. I've searched the forums and support sites for information on how to fix and none have managed to fix it so far.

Things I've tried: Date and time are correct. ESET virus is not running SSL checks and have disabled fully. Ran virus scan on PC and found no results. Updated FireFox and tried the Beta 34. Normally use FireFox in private mode and cleared cache. Tried FireFox in safe mode. Deleted and renamed cert8.db

Pretty much everything you could possibly suggest and FireFox refuses to grant me access to this website.


I've logged in to my email through Internet Explorer while ESET is active and I have no problem connecting. I believe this is an issue with FireFox. I cannot recall when this error started to appear but it is probably recent in the past month or so.

Please can this issue be addressed by Mozilla as there seems to be quite a few people having this problem. It does not seem to be third party causing the issue as FireFox is the only program having trouble connecting.

I've been getting this issue with outlook.com or mail.live.com when I try to access my email through FireFox. Below is the full error: This Connection is Untrusted You have asked Firefox to connect securely to dub120.mail.live.com, but we can't confirm that your connection is secure. Normally, when you try to connect securely, sites will present trusted identification to prove that you are going to the right place. However, this site's identity can't be verified. dub120.mail.live.com uses an invalid security certificate. The certificate is not trusted because no issuer chain was provided. (Error code: sec_error_unknown_issuer) I've been trying to access this site for a while using FireFox but I have had no luck. I've searched the forums and support sites for information on how to fix and none have managed to fix it so far. Things I've tried: Date and time are correct. ESET virus is not running SSL checks and have disabled fully. Ran virus scan on PC and found no results. Updated FireFox and tried the Beta 34. Normally use FireFox in private mode and cleared cache. Tried FireFox in safe mode. Deleted and renamed cert8.db Pretty much everything you could possibly suggest and FireFox refuses to grant me access to this website. I've logged in to my email through Internet Explorer while ESET is active and I have no problem connecting. I believe this is an issue with FireFox. I cannot recall when this error started to appear but it is probably recent in the past month or so. Please can this issue be addressed by Mozilla as there seems to be quite a few people having this problem. It does not seem to be third party causing the issue as FireFox is the only program having trouble connecting.

Chosen solution

This problem has recently been resolved. I believe Microsoft seems to have fixed the issue with their site and updated. The certificate scanner shows positive readings now.

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I doubt this is a Firefox problem, it's more likely Firefox is the only browser giving you an alert that something isn't quite right.

Click the site identity button - More Information - View Certificate https://support.mozilla.org/en-US/kb/how-do-i-tell-if-my-connection-is-secure

Look for 'Issued By' and post that information.

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When I first go to the website and login it shows my email and all of the emails I've been sent. At the top left it shows the green lock and says you are connected and it is secure. If I try to click any links or emails it just remains on the home screen with the list of my emails. None of the links direct anywhere but the address bar changes.

If I click refresh the page then shows "This Connection is Untrusted." and shows a yellow triangle with a !. At the top left it shows a greyed out globe with the text "This website does not supply identity information. Your connection to this website is not encrypted."

There is no issued by but before I click refresh it says Run by Microsoft Corporation.

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Make sure that the address still starts with the https:// protocol.

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Both https://www.outlook.com and https://www.mail.live.com redirect you to a longer link and the sign in page.

https://login.live.com/login.srf?wa=wsignin1.0&ct=1417341635&rver=6.1.6206.0&sa=1&ntprob=-1&wp=MBI_SSL_SHARED&wreply=https:%2F%2Fmail.live.com%2F%3Fowa%3D1%26owasuffix%3Dowa%252f&id=64855&snsc=1&cbcxt=mail

When I sign in it shows the following link: https://dub120.mail.live.com/default.aspx?id=64855&owa=1&owasuffix=owa%2f and the green lock saying connection secure. I can't do anything on this current URL. The page is frozen but I can see my emails and click links but nothing changes. Once I click refresh to try and get it to respond it says connection not secure like above.

All the links are using HTTPS.

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Chosen Solution

This problem has recently been resolved. I believe Microsoft seems to have fixed the issue with their site and updated. The certificate scanner shows positive readings now.