Resolving 'ERR_SSL_PROTOCOL_ERROR' on GitHub Pages: A Case Study in Software Development Measurement

When Your Secure Site Suddenly Isn't: Troubleshooting GitHub Pages SSL Errors

In the fast-paced world of web development, a site that worked perfectly yesterday can suddenly present a baffling error today. This is a common scenario that impacts developer productivity and, by extension, key metrics in software development measurement. A recent discussion on GitHub's Community forum highlights just such a challenge: a custom domain on GitHub Pages suddenly failing with an "ERR_SSL_PROTOCOL_ERROR."

The Sudden SSL Breakdown: A Developer's Dilemma

User happydylansmith faced a perplexing issue: their site, www.nbatop80.com, which had been operational for weeks, abruptly displayed "This site can’t provide a secure connection" or "Suspicious Site Blocked" errors. As a self-proclaimed "novel at this," the developer was understandably lost. The site used Bluehost for its domain and GitHub Pages for hosting, with a custom domain and enforced HTTPS enabled – settings that had previously worked without a hitch.

Community-Driven Solutions for Secure Connections

The community quickly rallied, offering precise troubleshooting steps that are invaluable for anyone managing custom domains on GitHub Pages:

• DNS Configuration Deep Dive: The most common culprit for SSL issues on custom domains is incorrect DNS settings.
  • Your root domain (e.g., nbatop80.com) must use A records, pointing directly to GitHub's IP addresses (185.199.108.153, 185.199.109.153, 185.199.110.153, 185.199.111.153).
  • Your www subdomain (e.g., www.nbatop80.com) should be a CNAME record, pointing to your GitHub Pages username/organization domain (e.g., happydylansmith.github.io). Crucially, avoid extra A/AAAA records for the www subdomain if it's a CNAME.
• GitHub Pages Settings Review: Sometimes, a simple toggle can resolve the issue.
  • Navigate to your repository's Settings > Pages.
  • Remove and then re-add your custom domain.
  • Ensure that "Enforce HTTPS" is re-enabled.
• The Waiting Game & Cache Clearing: DNS changes and SSL certificate provisioning aren't instantaneous.
  • After making changes, wait 30–60 minutes for DNS records to propagate and for GitHub to reissue/renew the SSL certificate.
  • Clear your browser's cache and your local DNS cache to ensure you're not seeing outdated information.

As mecodeatlas later confirmed, the site eventually loaded normally over HTTPS, suggesting the issue was resolved through these steps or naturally cleared after a waiting period. For further reading on resolving SSL errors, you might find resources like this guide on fixing ERR_SSL_PROTOCOL_ERROR helpful.

The Importance of Diligent Deployment Practices

This community insight underscores the critical role of accurate configuration and understanding of DNS/SSL for reliable web deployments. For teams focused on software development measurement, issues like this highlight the need for robust deployment pipelines and clear documentation. Proactive monitoring and a solid grasp of these underlying technologies contribute directly to successful project delivery and positive engineering reports.

Key Takeaways for Robust Web Deployments

• Verify DNS Records: Always double-check A records for root domains and CNAME records for subdomains against GitHub Pages' requirements.
• GitHub Pages Settings: Leverage the "remove/re-add custom domain" and "Enforce HTTPS" toggles as a first troubleshooting step.
• Patience and Cache Clearing: Allow time for changes to propagate and clear local caches to see the latest state.
• Community Support: Don't hesitate to reach out to developer communities for quick and effective solutions.