https://community.plus.net/t5/My-Router/Changed-router-to-Plusnet-model-now-getting-Outlook-warning-re/m-p/1971304#M38570 <P>Does this describe your issue -&nbsp;<A href="https://support.microsoft.com/en-gb/topic/-the-name-on-the-security-certificate-is-invalid-or-does-not-match-the-name-of-the-site-error-in-outlook-in-a-dedicated-or-itar-office-365-environment-873b8392-9f5c-8a27-311b-abdc224dc118#:~:text=Generally%2C%20this%20issue%20occurs%20when,SSL)%20certificate%20for%20the%20website." target="_blank">"The name on the security certificate is invalid or does not match the name of the site" error in Outlook in a dedicated or ITAR Office 365 environment - Microsoft Support</A></P> <P>I would be surprised if this is a router caused problem - there is some (remote?) possibility that this is related a DNS look up issue with the auto-discovery service.</P> Thu, 23 May 2024 16:46:30 GMT Townman 2024-05-23T16:46:30Z https://community.plus.net/t5/My-Router/Changed-router-to-Plusnet-model-now-getting-Outlook-warning-re/m-p/1970558#M38520 <P>Hi - changed my router back from Draytek to the provided Plusnet Hub Two due to OpenReach line issues (to simplify their testing of line).</P> <P>Noticed that am now getting intermittent error messages related to outlook.office365.com:</P> <P>'Security Alert ... outlook.office365.com... problem with the site's security certificate...the name on the security certificate is invalid or does not match the name of the site" and options are Yes/No/View Cert. Looking at the cert it was issued to cloudflare-dns.com.</P> <P>Any ideas? the Plusnet router shows the usual 212.x.x.x stuff for DNS, though I also note that the Firewall defaults to On.</P> <P>Thanks.</P> <P>(incidentally, despite 48 down / 10 up speed showing, web pages on my PC taking ages to load - tracert to 212.x.x.x.x 's timing out and to 8.8.8.8 taking ages).</P> Sat, 18 May 2024 11:31:38 GMT https://community.plus.net/t5/My-Router/Changed-router-to-Plusnet-model-now-getting-Outlook-warning-re/m-p/1970558#M38520 mdplus 2024-05-18T11:31:38Z https://community.plus.net/t5/My-Router/Changed-router-to-Plusnet-model-now-getting-Outlook-warning-re/m-p/1971304#M38570 <P>Does this describe your issue -&nbsp;<A href="https://support.microsoft.com/en-gb/topic/-the-name-on-the-security-certificate-is-invalid-or-does-not-match-the-name-of-the-site-error-in-outlook-in-a-dedicated-or-itar-office-365-environment-873b8392-9f5c-8a27-311b-abdc224dc118#:~:text=Generally%2C%20this%20issue%20occurs%20when,SSL)%20certificate%20for%20the%20website." target="_blank">"The name on the security certificate is invalid or does not match the name of the site" error in Outlook in a dedicated or ITAR Office 365 environment - Microsoft Support</A></P> <P>I would be surprised if this is a router caused problem - there is some (remote?) possibility that this is related a DNS look up issue with the auto-discovery service.</P> Thu, 23 May 2024 16:46:30 GMT https://community.plus.net/t5/My-Router/Changed-router-to-Plusnet-model-now-getting-Outlook-warning-re/m-p/1971304#M38570 Townman 2024-05-23T16:46:30Z https://community.plus.net/t5/My-Router/Changed-router-to-Plusnet-model-now-getting-Outlook-warning-re/m-p/1971496#M38590 <P>Hi - thanks for your reply.</P> <P>No, it turns out that it is not just Outlook which is affected. I tried to open a cloud-stored PDF file from within Acrobat and got pretty much the same message, again indicating Cloudflare.</P> <P>The bizarre thing is that this is strangely intermittent - I can go the whole day with no problems then suddenly e.g. Outlook will keep popping up the Cert message.</P> Sat, 25 May 2024 08:38:01 GMT https://community.plus.net/t5/My-Router/Changed-router-to-Plusnet-model-now-getting-Outlook-warning-re/m-p/1971496#M38590 mdplus 2024-05-25T08:38:01Z