I'll show you how to implement a generic error modal system that handles errors thrown in middleware. The key is to use a combination of middleware error handling, cookies/headers, and a global error modal component.

This implementation provides a comprehensive error handling system for middleware errors:

Key Features:

1. Middleware Error Handling: The middleware catches errors and stores them in cookies that the client can read
2. Global Error Context: A React context manages error state across the application
3. Error Modal Component: A reusable modal that displays errors to users
4. Automatic Error Detection: The system automatically checks for middleware errors on page load and route changes
5. Multiple Error Sources: Handles errors from middleware, API calls, and client-side code

How It Works:

1. Middleware: Catches errors and sets a cookie with error information
2. Error Provider: Checks for error cookies and manages global error state
3. Error Modal: Displays errors in a user-friendly modal dialog
4. Automatic Cleanup: Error cookies are automatically cleared after being read

Usage Examples:

• Protected Routes: Try accessing /dashboard without authentication
• Invalid Tokens: Test with invalid authentication tokens
• API Errors: Simulate API failures
• Client Errors: Trigger client-side errors manually

The system gracefully handles all error scenarios and provides consistent user feedback through the modal interface.