Troubleshooting¶

Common .NET isolated worker problems with direct diagnosis and remediation steps.

flowchart TD
    A[Configuration] --> B[Build]
    B --> C[Deploy]
    C --> D[Observe]

Topic/Command Groups¶

Function not discovered after deploy¶

• Confirm FUNCTIONS_WORKER_RUNTIME=dotnet-isolated.
• Check startup exceptions in log stream.
• On Linux Consumption, az functionapp log tail can fail because scm/Kudu endpoints are not available; use Application Insights queries instead.

az functionapp log tail --name "$APP_NAME" --resource-group "$RG"

Startup failure due to package mismatch¶

• Align worker SDK and extension package versions.
• Rebuild and republish with clean output.

dotnet clean
dotnet build --configuration Release
dotnet publish --configuration Release --output ./publish
func azure functionapp publish "$APP_NAME"

HTTP 500 from serialization¶

• Validate request body parsing and response encoding.
• Ensure HttpResponseData is returned on all code paths.

See Also¶

• .NET Language Guide
• .NET Runtime
• .NET Isolated Worker Model
• Recipes Index

Sources¶

• Azure Functions .NET isolated worker guide
• Azure Functions host.json reference