Azure Static WebApp: "404: Not Found" suddenly

Question

Azure Static WebApp: "404: Not Found" suddenly

Jesus Garcia Gutierrez 20

Hi there! I have a website, fosfoyesos.info, powered by SWA.

Until yesterday, the website was fine, but today I'm getting a 404 error without making any changes.

I've deployed in order to fix the error, but it is still there.

Any idea? Thank you.

Golla Venkata Pavani 6,085 Reputation points Microsoft External Staff Moderator

2026-05-12T13:50:31.0633333+00:00
Hi @Jesus Garcia Gutierrez

Thank you for reaching us regarding the issue that a sudden "404: Not Found" error on your custom domain (fosfoyesos.info), especially when no changes were made, is typically related to the custom domain mapping, DNS resolution, or binding state.

The default *.azurestaticapps.net URL should continue serving your site content. The Azure "404 Web Site not found" page on the custom domain indicates that Azure does not yet fully recognize or route traffic to your app for that hostname.
Official Guidance from Microsoft Docs

Verify the default URL first Go to your Static Web App in the Azure portal and confirm the site loads correctly at the autogenerated URL. This isolates the issue to the custom domain configuration.

Check and re-validate the custom domain binding

Navigate to your Static Web App > Settings > Custom domains.

Review the status of fosfoyesos.info. Look for any warnings, pending states, or validation issues.

Recommended reset if issues appear: Remove the custom domain and add it again. This clears potential internal mapping or certificate binding problems.

DNS Configuration (Critical Step) Follow the exact requirements in the docs:

For subdomains (e.g., www), use a CNAME record pointing to your app's default hostname (<your-app>.azurestaticapps.net).

For apex/root domains (like fosfoyesos.info), options include A record + verification TXT record, or supported alias/ANAME records.

Never mix conflicting A and CNAME records for the same host.

DNS changes can take time to propagate (up to 48 hours in some cases). Use tools like WhatsMyDNS to verify.

Add/Validate the Domain in Azure

In the portal: Custom domains > + Add > Custom domain on other DNS.

Enter the domain and follow the validation steps (Azure provides the exact records needed).

After successful validation, wait for the managed SSL/TLS certificate to provision automatically.

Routing Configuration (If Needed) If the issue affects specific routes (especially in SPAs), ensure staticwebapp.config.json is in your build output folder with proper fallback rules. The older routes.json is deprecated.

Reference:
https://learn.microsoft.com/en-us/azure/static-web-apps/custom-domain-external
https://learn.microsoft.com/en-us/troubleshoot/azure/app-service/connection-issues-with-ssl-or-tls/troubleshoot-custom-domain-issues-azure-app-service
https://learn.microsoft.com/en-us/azure/static-web-apps/custom-domain

Kindly let us know if the above helps or you need further assistance on this issue.

Please "upvote" if the information helped you. This will help us and others in the community as well.
Jesus Garcia Gutierrez 20 Reputation points

2026-05-12T19:11:13.6066667+00:00

Hi Golla! I really appreciate your help. However, I've visited https://black-flower-04ce41403.3.azurestaticapps.net/ (Azure's default URL), and it shows the same error message.

The issue affects all fosfoyesos.info routes. I get 404 in any of the resources I’ve seen before.

Thank you for your help, Golla! Let's see if we can solve this problem, or if another one is having the same problem. Greetings!
Jesús.
Jesus Garcia Gutierrez 20 Reputation points

2026-05-14T00:09:34.8766667+00:00

Here’s the repo. As you can see in GitHub Actions, I couldn't have made the 404 issue. It occurred suddenly, without any code changes.
Jesus Garcia Gutierrez 20 Reputation points

2026-05-14T08:58:25.67+00:00

Hi there! I think I have found an answer to this problem, but I don't know how to solve it.
Visiting "Environment variables" I see this message:
La suscripción "[suscription_id]" está deshabilitada y por tanto marcada como de solo lectura. No es posible realizar ninguna acción de escritura en esta suscripción hasta que se vuelva a habilitar. Error 409.
The subscription “[subscription_id]” is disabled and therefore marked as read-only. You cannot perform any write operations on this subscription until it is re-enabled. Error 409.
But I don't understand why, since I'm using Azure for Students and the fosfoyesos.info SWA is using the free plan.
I hope we can find a solution, cheers.
Jesús.

Answer accepted by question author

Golla Venkata Pavani 6,085 Microsoft External Staff Moderator

Hi @Jesus Garcia Gutierrez

Thank you for the update. This explains the sudden 404 error perfectly. The root cause is that your Azure subscription (the one hosting the Static Web App) is currently disabled and operating in read-only mode. Because of this, Azure cannot process deployments, apply configuration changes, or properly serve the custom domain binding and SSL certificate, which results in the “404 Web Site not found” page. This situation is common with Azure for Students subscriptions when the $100 credit has been exhausted, the 12-month validity period has expired, or the subscription was accidentally canceled or hit a service limit. Even though Azure Static Web Apps may use a free tier, a disabled subscription still prevents normal operation of the service.

To resolve the issue, please go to the Azure Portal > Subscriptions and verify the status of your subscription (it will likely show as “Disabled”). The recommended solution is usually to reactivate or upgrade the subscription to Pay-As-You-Go, which allows continued use beyond the student subscription limits. If needed, you can also contact Azure Support through Help + support > New support request and select the Billing/Subscription category to request reactivation assistance. After the subscription becomes active again, redeploy the application (even without code changes) and then go to Settings > Custom domains to remove and re-add the fosfoyesos.info domain if necessary so Azure can refresh the domain binding and SSL certificate. Please note that DNS propagation and certificate reissuance may take several minutes or, in some cases, a few hours.

Reference:
https://learn.microsoft.com/en-us/azure/cost-management-billing/manage/azurestudents-subscription-disabled
https://learn.microsoft.com/en-us/azure/cost-management-billing/manage/subscription-disabled

Kindly let us know if the above helps or you need further assistance on this issue.

Please "accept" if the information helped you. This will help us and others in the community as well.

Jesus Garcia Gutierrez 20 Reputation points

2026-05-14T18:53:21.66+00:00

Thank you so much, @Golla Venkata Pavani , fantastic answer! fosfoyesos.info is online now, let's go!!! 🤞😊

1 additional answer

Your answer

Jesus Garcia Gutierrez 20 Reputation points

2026-05-12T19:11:13.6066667+00:00

Hi Golla! I really appreciate your help. However, I've visited https://black-flower-04ce41403.3.azurestaticapps.net/ (Azure's default URL), and it shows the same error message.

The issue affects all fosfoyesos.info routes. I get 404 in any of the resources I’ve seen before.

Thank you for your help, Golla! Let's see if we can solve this problem, or if another one is having the same problem. Greetings!
Jesús.
Jesus Garcia Gutierrez 20 Reputation points

2026-05-14T00:09:34.8766667+00:00

Here’s the repo. As you can see in GitHub Actions, I couldn't have made the 404 issue. It occurred suddenly, without any code changes.
Jesus Garcia Gutierrez 20 Reputation points

2026-05-14T08:58:25.67+00:00

Hi there! I think I have found an answer to this problem, but I don't know how to solve it.
Visiting "Environment variables" I see this message:
La suscripción "[suscription_id]" está deshabilitada y por tanto marcada como de solo lectura. No es posible realizar ninguna acción de escritura en esta suscripción hasta que se vuelva a habilitar. Error 409.
The subscription “[subscription_id]” is disabled and therefore marked as read-only. You cannot perform any write operations on this subscription until it is re-enabled. Error 409.
But I don't understand why, since I'm using Azure for Students and the fosfoyesos.info SWA is using the free plan.
I hope we can find a solution, cheers.
Jesús.
Jesus Garcia Gutierrez 20 Reputation points

2026-05-14T18:53:21.66+00:00

Thank you so much, @Golla Venkata Pavani , fantastic answer! fosfoyesos.info is online now, let's go!!! 🤞😊

Answer 1

A transient platform or caching issue is the most likely cause when an Azure Static Web App that was working suddenly starts returning a generic Azure 404 without any code changes, especially if redeploying does not change the behavior.

In similar cases, the issue has resolved on its own after some time without any configuration changes, suggesting delayed cache invalidation or a temporary platform problem. Because Azure Static Web Apps automatically handles cache invalidation after deployments, no manual purge is normally required.

Recommended actions:

Wait and recheck the site periodically (both the default *.azurestaticapps.net URL and the custom domain).
If the issue persists for an extended period, open a support request with Azure Support so they can check the specific Static Web App resource and deployment history.

References:

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Azure Static WebApp: "404: Not Found" suddenly

1 additional answer

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