doh.xfinity.com Certificate Error: How to Fix it

Recently, a lot of users had their antivirus sending notifications about a certificate error for doh.xfinity.com. Even when accessing the website, they were informed of the certificate issue and that it expired on Friday, September 8, 2023.

In most cases, Kaspersky antivirus flagged the SSL connection and reported the expired certificate. It’s mostly a problem on the server side, but DNS queries and requests, or an incorrect date and time, could also be the culprit.

What is the doh.xfinity.com certificate error?

The error indicates that the certificate assigned to the website has expired or is not properly configured. Subsequently, an encrypted connection cannot be established between the server and the application, say Adobe AcroCEF or Overwolf.

How do I fix the doh.xfinity.com certificate error?

Before we start with the slightly complex solutions, try these quick ones:

If you must access the website, click Advanced and then select Proceed in your browser.
To get rid of the antivirus notifications, disable the app trying to connect to doh.xfinity.com. Or you could disable the app from loading at boot and restart the PC.

1. Set the correct date and time

Press Windows + I to open Settings, go to Time & language from the navigation pane, and select Date & time.
If the time is configured incorrectly, disable the toggle for Set time automatically, and click the Change button next to Set date and time manually.
Now, set the current time and date, and then click Change for the new time to apply.

Also, as a workaround, you can change the date and time manually to a point when the certificate was valid and check whether that helps access doh.xfinity.com. This also helps with certificate errors in Edge.

2. Change the DNS server

Press Windows + R to open Run, type ncpa.cpl in the text field, and hit Enter .
Right-click on the active network adapter and select Properties.
Select Internet Protocol Version 4 (TCP/IPv4), and click Properties.
Select Use the following DNS server addresses, and enter the following details in the fields:
- Preferred DNS server: 8.8.8.8
- Alternate DNS server: 8.8.4.4
Click OK to save the changes and reboot the PC.

Often, an issue with the DNS server can lead to the doh.xfinity.com certificate error. Also, it’s possible to use the fastest DNS server near you instead of Google’s DNS.

3. Contact Xfinity support

他に何も問題が解決しない場合は、Xfinity サポートにお問い合わせください。彼らは問題が自分たちの側にあることをすでに認識していますが、同じことを知らせることでより迅速な行動が取れる可能性があります。

また、doh.xfinity.com で別のエラーメッセージ (HTTP エラー 400 など) が表示された場合は、その旨をサポートチームに通知してください。そうですね

doh.xfinity.com であれ、別の Web サイトであれ、証明書エラーは通常、サイト所有者によって 1 ～ 2 日以内に修正されますが、問題がないか確認してください。誰が何と言おうと、ウイルス対策ソフトは絶対に無効にしないでください。

ただし、これは Web サイトのセキュリティが確実である場合にのみ行ってください。

ご質問がある場合、または効果があったことを共有したい場合は、下にコメントを入力してください。

doh.xfinity.com Certificate Error: How to Fix it