# Warning: stream_wrapper_register(): class 'App\Storage\CustomStream' does not exist in /var/www/app/src/Storage/StreamManager.php on line 10

- **ID:** `php/stream-wrapper-register-invalid-class`
- **Domain:** php
- **Category:** runtime_error
- **Verification:** ai_generated
- **Fix Rate:** 88%

## Root Cause

The class passed to stream_wrapper_register() has not been loaded or defined before the call, often due to missing autoloader configuration or a typo in the class name.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| PHP 8.1.31 | active | — | — |
| PHP 8.2.19 | active | — | — |
| PHP 8.3.5 | active | — | — |

## Workarounds

1. **Ensure the class is autoloaded before registration by adding a use statement or require: require_once __DIR__ . '/CustomStream.php'; stream_wrapper_register('custom', 'App\Storage\CustomStream');** (90% success)
   ```
   Ensure the class is autoloaded before registration by adding a use statement or require: require_once __DIR__ . '/CustomStream.php'; stream_wrapper_register('custom', 'App\Storage\CustomStream');
   ```
2. **Check composer autoload configuration: ensure the namespace 'App\Storage' maps to the correct directory in composer.json and run composer dump-autoload.** (85% success)
   ```
   Check composer autoload configuration: ensure the namespace 'App\Storage' maps to the correct directory in composer.json and run composer dump-autoload.
   ```

## Dead Ends

- **** — Adding require_once for the class file after the stream_wrapper_register() call does not work because the function checks for class existence at call time. (90% fail)
- **** — Using spl_autoload_register() with a custom autoloader that has a lower priority may never be triggered for the stream wrapper class if another autoloader returns false first. (65% fail)