Internal server error

Question

Internal server error

Matej Jakubčík 130

I deployed a promot flow to a demo web app in Azure connected through github. It worked fine but after one commit the fetch function onto my web return html code instead of json. The html code stated internal server error. I tried to revert the changes I made in that commit but it didnt help. Can you please help me fix this issue? Should I try restarting the app?

Prashanth Veeragoni 3,710 Reputation points Microsoft External Staff

2025-04-15T13:33:01.47+00:00
Hi Matej Jakubčík,

Thanks for the detailed context — yes, I can help with this deployment issue.

You're getting an Internal Server Error, and your frontend fetch call is receiving HTML instead of JSON, which typically suggests the backend is crashing or not handling the request as expected.

Here’s a step-by-step checklist to troubleshoot and fix it:

1.Restart the Web App (Yes)

Yes, restart the Azure App Service. It’s a quick and harmless step that you can resolve temporary issues like:

·       Caching issues

·       Port conflicts

·       Stale app state after a bad deployment

You can do this via:

·       Azure Portal → App Services → Your App → Restart

·       Or use Azure CLI:

az webapp restart --name YourAppName --resource-group YourResourceGroup

2.Validate the Commit Changes

Even though you reverted the commit, GitHub Actions or Azure may not have fully redeployed cleanly. Double-check:

·       Was the GitHub Action successful after the revert?

·       Was requirements.txt or startup command changed?

·       Is app.py or equivalent entry point still correctly named?

Also make sure:

·       Startup command is not missing or incorrect in Azure Configuration → General settings → Startup Command.

3.Test the API Endpoint Directly

Use curl or Postman to test the backend endpoint directly:

curl -X POST https://<your-app>.azurewebsites.net/api/your-endpoint \ -H "Content-Type: application/json" \ -d '{"input": "Hello"}'

If this returns HTML, the server is failing to process the request. This can help isolate whether it’s a frontend or backend issue.

Hope this helps, do let me know if you have any further queries.

Thank you!
Prashanth Veeragoni 3,710 Reputation points Microsoft External Staff

2025-04-16T15:56:48.8866667+00:00

Hi Matej Jakubčík,

Following up to see if the above suggestion was helpful. And, if you have any further queries do let me know.

Thank you!
Prashanth Veeragoni 3,710 Reputation points Microsoft External Staff

2025-04-17T16:28:33.8566667+00:00

Hi Matej Jakubčík,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution, please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.

Thank you!

Your answer

Prashanth Veeragoni 3,710 Reputation points Microsoft External Staff

2025-04-15T13:33:01.47+00:00

Hi Matej Jakubčík,

Thanks for the detailed context — yes, I can help with this deployment issue.

You're getting an Internal Server Error, and your frontend fetch call is receiving HTML instead of JSON, which typically suggests the backend is crashing or not handling the request as expected.

Here’s a step-by-step checklist to troubleshoot and fix it:

1.Restart the Web App (Yes)

Yes, restart the Azure App Service. It’s a quick and harmless step that you can resolve temporary issues like:

· Caching issues

· Port conflicts

· Stale app state after a bad deployment

You can do this via:

· Azure Portal → App Services → Your App → Restart

· Or use Azure CLI:

az webapp restart --name YourAppName --resource-group YourResourceGroup

2.Validate the Commit Changes

Even though you reverted the commit, GitHub Actions or Azure may not have fully redeployed cleanly. Double-check:

· Was the GitHub Action successful after the revert?

· Was requirements.txt or startup command changed?

· Is app.py or equivalent entry point still correctly named?

Also make sure:

· Startup command is not missing or incorrect in Azure Configuration → General settings → Startup Command.

3.Test the API Endpoint Directly

Use curl or Postman to test the backend endpoint directly:

curl -X POST https://<your-app>.azurewebsites.net/api/your-endpoint \ -H "Content-Type: application/json" \ -d '{"input": "Hello"}'

If this returns HTML, the server is failing to process the request. This can help isolate whether it’s a frontend or backend issue.

Hope this helps, do let me know if you have any further queries.

Thank you!
Prashanth Veeragoni 3,710 Reputation points Microsoft External Staff

2025-04-16T15:56:48.8866667+00:00

Hi Matej Jakubčík,

Following up to see if the above suggestion was helpful. And, if you have any further queries do let me know.

Thank you!
Prashanth Veeragoni 3,710 Reputation points Microsoft External Staff

2025-04-17T16:28:33.8566667+00:00

Hi Matej Jakubčík,

We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution, please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.

Thank you!

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Internal server error

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