GitHub Pages custom domain always reports InvalidDNSError

[yoshii91]

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Hello GitHub Support,

I am experiencing an issue with GitHub Pages for my repository.

Repository:
https://github.com/yoshii91/homepage_part2

GitHub Pages configuration:

• Source: main branch
• Folder: /docs

Custom domain:
wakai-fusuma.jp

Current issue:

GitHub Pages always reports:

DNS check unsuccessful

Both wakai-fusuma.jp and its alternate name are improperly configured.

Domain's DNS record could not be retrieved.
(InvalidDNSError)

HTTPS cannot be enabled.

Browsers display:

NET::ERR_CERT_COMMON_NAME_INVALID

SSL inspection shows that the server returns the default certificate:

Common Name: *.github.io

instead of a certificate for wakai-fusuma.jp.

I have already verified the following:

• GitHub Pages deploys successfully.
• Source is main -> /docs.
• docs/CNAME exists.
• CNAME is generated automatically by GitHub.
• A records point to:
  185.199.108.153
  185.199.109.153
  185.199.110.153
  185.199.111.153
• www CNAME points to yoshii91.github.io
• DNS propagation is complete.
• nslookup resolves correctly.
• DNSChecker confirms A and CNAME records worldwide.
• No AAAA records.
• No CAA records.
• Route53 is not used.
• CloudFront is not used.
• The custom domain has been removed and added again.
• I have waited more than 24 hours.

Despite this, GitHub Pages still reports InvalidDNSError and never issues a certificate for the custom domain.

Could you please check whether there is an issue with GitHub's domain validation or certificate provisioning for this repository?

Thank you.

Additional information:

• Repository: https://github.com/yoshii91/homepage_part2
• Custom domain: wakai-fusuma.jp
• www subdomain: www.wakai-fusuma.jp

Could someone from GitHub please check whether this domain is stuck in GitHub Pages validation or certificate provisioning?

[yal212]

I checked the public DNS, and it looks correct from here:

• wakai-fusuma.jp resolves to GitHub Pages’ four A records.
• www.wakai-fusuma.jp is a CNAME to yoshii91.github.io.
• I do not see AAAA or CAA records.

However, this URL returns 404:

https://raw.githubusercontent.com/yoshii91/homepage_part2/main/docs/CNAME

So GitHub may not currently see a docs/CNAME file on the main branch, even if one exists locally or was generated previously.

I would check these first:

1. Confirm that docs/CNAME is committed and pushed to main.

2. Confirm the file contains only:

   wakai-fusuma.jp
   

3. In the repository settings, remove the custom domain, save, then add wakai-fusuma.jp again.

4. Wait for Pages to regenerate the CNAME file and retry the DNS check.

5. If the file still does not appear at the raw URL above, GitHub Pages is probably not publishing from the path/branch you expect.
   The DNS side appears fine, so I would focus on the Pages source/CNAME state in the repository.

[Mr-Nilarnab]

Since the public DNS appears to be resolving correctly, the remaining issue may be related to GitHub Pages' validation process rather than the DNS records themselves.

A few additional things worth checking:

Ensure the repository doesn't contain another CNAME file (for example, in the repository root) that could conflict with the one in docs/.
Verify that wakai-fusuma.jp isn't already configured as a custom domain for another GitHub Pages site, since a domain can only be associated with one Pages site at a time.
Confirm that your DNS provider isn't enabling features such as proxying, URL forwarding, or DNS flattening that could interfere with GitHub's validation.
If you've recently modified the domain configuration several times, give GitHub Pages a little more time before making additional changes, as repeated updates can delay certificate provisioning.

If all of those checks pass and InvalidDNSError continues despite correct public DNS records, this is likely something only GitHub Support can investigate. Providing the repository name, custom domain, screenshots of the Pages settings, and the results of dig/nslookup in a support ticket should help them determine whether the domain validation or certificate provisioning process is stuck on GitHub's side.