Azure Web App Custom Domain - Failed to configure SSL binding due to error: Parameter Thumbprint is null or empty.

Hi @Dusty Beach ,

Thank you for submitting your question on Microsoft Q&A.

If you’re seeing the error “Parameter Thumbprint is null or empty,” it means Azure can’t find a valid SSL certificate to link with your custom domain. In your screenshot, the Certificate dropdown says:

No certificates match the selected domain. Add a new certificate below and bind it with the domain.

So, even though your domain is verified (green check), there’s no certificate for it yet the thumbprint shows up only after a certificate is created.

Why is this happening?

• The App Service Managed Certificate hasn’t been made yet (or didn’t get created properly).
• DNS is verified, but the certificate request didn’t finish.
• Sometimes, the managed certificate process gets stuck if you just deleted and re-added the domain.

How can you fix it?

1. Check for an existing certificate: Head to Azure Portal > App Service > TLS/SSL Settings > Private Key Certificates (.pfx). If there’s no certificate for your domain, you’ll need to create one.
2. Create a Managed Certificate: In TLS/SSL Settings, click Create App Service Managed Certificate, select your domain, and hit Create. It can take up to 10 minutes. Managed certs only work for non-wildcard domains and not for naked domains without a CNAME.
3. Bind the certificate: Once the cert shows up, go to Custom Domains → Add TLS/SSL Binding. The Certificate dropdown should now list the new cert. Pick SNI SSL and add the binding.
4. If the cert doesn’t show up: Try deleting the custom domain from App Service, re-add it, verify DNS, and then try creating the cert again.

Alternative option: Use your own certificate. If managed certs keep failing, buy an SSL cert from a provider, upload it in TLS/SSL Settings, and bind it to your domain.

Heads up on common issues:

• Managed certs don’t support apex domains unless you use an ALIAS/ANAME record.
• If you deleted the domain before, the cert might be stuck re-adding usually fixes it.
• Make sure your App Service is on Basic or higher SSL isn’t supported on the Free tier.

 If you’re seeing the error “Parameter Thumbprint is null or empty,” it means Azure can’t find a valid SSL certificate to link with your custom domain. In your screenshot, the Certificate dropdown says:

 Reference :

https://learn.microsoft.com/en-us/azure/app-service/configure-ssl-bindings?wt.mc_id=knowledgesearch_inproduct_azure-cxp-community-insider#add-the-binding

https://learn.microsoft.com/en-us/troubleshoot/azure/app-service/troubleshoot-azure-app-service-certificates?wt.mc_id=knowledgesearch_inproduct_azure-cxp-community-insider#step-by-step-troubleshooting-flow

https://learn.microsoft.com/en-us/troubleshoot/azure/app-service/troubleshoot-azure-app-service-certificates?wt.mc_id=knowledgesearch_inproduct_azure-cxp-community-insider#step-4-check-app-service-certificate-binding-configuration

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Hi @Dusty Beach ,

Could you please review my comments, follow the steps, and let me know whether your issue has been resolved?