JavaScript errors in blocks are contained by React error boundaries, preventing them from breaking the entire editor interface. Generic error messages require console inspection to identify specific issues.
Enable SCRIPT_DEBUG in wp-config.php to access detailed React error information in development mode. This provides specific error messages, function names, and line numbers for effective debugging.
The browser console reveals the exact nature of JavaScript errors, including undefined functions, syntax issues, and runtime problems that aren’t caught during the build process.