VM stopped functioning, tried restart, no luck

Hello Zaffar,

Thank you for reaching out, and I’m sorry you’re experiencing this disruption.

An HTTP 500 Internal Server Error indicates that the web server on your VM is reachable and running, but the application hosted on it is failing to process the request. This is why restarting the VM alone does not resolve the issue, as the root cause typically lies at the application layer rather than the underlying infrastructure.

Please follow the steps below to help isolate the issue:

Check Application & Event Logs On your VM, open Event Viewer → Windows Logs → Application and review any errors occurring at the time the HTTP 500 error is generated. These logs usually provide the most direct indication of the failure cause.

Enable Detailed Error Logging (IIS) If you are using IIS, enable Failed Request Tracing to capture detailed request-level failure information:

https://learn.microsoft.com/en-us/previous-versions/troubleshoot/iis/troubleshoot-failed-requests-using-tracing-in-iis-7

Review IIS Logs IIS logs are typically located at: C:\inetpub\logs\LogFiles\W3SVC1\ Please check for entries with status code 500 and review the corresponding sub-status code as this helps narrow down the exact cause.

Check Application Logs (ASP.NET / Core Applications) If the application is built on ASP.NET or ASP.NET Core, please review application-specific logs or stdout logs, as startup or runtime exceptions are often captured there.

Validate Application Service Health Ensure that the relevant service or application pool is running and has not stopped or crashed. If applicable, restart the application pool or service instead of the entire VM.

Verify Recent Changes Please confirm if any recent changes were made, such as application deployment, configuration updates, certificate changes, or runtime upgrades, as these commonly lead to HTTP 500 errors.

Check System Resources Please also verify CPU, memory, and disk utilization on the VM, as resource exhaustion can sometimes lead to application failures.

Helpful Microsoft Documentation:

https://learn.microsoft.com/en-us/aspnet/core/test/troubleshoot-azure-iis?view=aspnetcore-10.0

https://learn.microsoft.com/en-us/troubleshoot/azure/virtual-machines/windows/troubleshoot-app-connection

To further assist you in isolating the issue, could you please confirm the following details:

• Are you able to connect to the VM via RDP, or is the issue only occurring when accessing the application through the URL?
• Is the VM showing as “Running” in the Azure Portal, and is it responding to network requests?
• Are you consistently receiving the HTTP 500 error? If possible, please share a screenshot or the exact error message.
• Are you able to access the application from within the VM itself (e.g., via localhost or internal browser)?
• When did this issue begin, and were there any recent changes prior to the issue such as deployments, patches, or configuration updates?
• Is this issue isolated to this specific VM, or are other VMs or applications also affected?
• Have you reviewed the application or web server logs (IIS / Apache / Nginx)? If so, are there any specific errors or warnings?
• Is the error occurring across all URLs, or only specific endpoints of the application?

Once we have the above details, we will be able to narrow down the root cause more precisely and proceed with further troubleshooting.

Additionally, could you please check private message and provide necessary details.