Detecting AutoCaptured Errors in Web Apps

What is AutoCapturedError in Web apps?

AutoCapturedError represents an unhandled JavaScript exception that bubbled up to the global window.onerror or unhandledrejection handlers. These are fatal crashes in the execution context.

Why it matters

Unhandled exceptions often break the execution of the main thread, resulting in half-rendered UIs, broken buttons, or the infamous "White Screen of Death" in modern single-page applications.

Why does this happen?

Null Reference Errors

The classic "Cannot read properties of undefined" or "undefined is not a function". This occurs when the frontend assumes an API response contains a specific property, but it is null or missing.

Lazy Loading Failures

When users navigate to a new route that relies on a lazy-loaded Webpack chunk, but that chunk fails to download (due to a new deployment replacing the hash, or a network drop), an unhandled module resolution error is thrown.

Third-Party Script Crashes

A buggy update to a third-party tracking pixel or ad widget throws a global exception, polluting your application's execution context.

How to fix it using Appxiom

• Analyze stack trace: Appxiom provides the exact minified and source-mapped stack trace pointing directly to the line of JavaScript/TypeScript code that triggered the issue.
• Trace activity trail: The activity trail provides a chronological list of user interactions (clicks, route changes) and network calls that occurred right before the issue, helping developers reproduce the exact user journey.