Undefined property: Illuminate\Auth\AuthManager::$id in Laravel 5.5.

The error message "Undefined property: Illuminate\Auth\AuthManager::$id" in Laravel 5.5 typically occurs when you try to access a property or method that does not exist on the given class. In this case, it seems that someone is trying to access a property named $id on the Illuminate\Auth\AuthManager class.

The AuthManager class is the facade for the Auth instance in Laravel, which is used to handle authentication and authorization. This class does not have a $id property, and trying to access it will result in the error message you're seeing.

To fix this issue, you need to identify where in your code you're trying to access this non-existent property and correct it. Here are some common places where this error might occur:

In a controller method: If you're trying to access the user ID in a controller method, you should use the auth() helper function to get the authenticated user instance, and then access the id property on that instance. For example:

public function myMethod()
{
    $userId = auth()->user()->id;
    // ...
}

In a view: If you're trying to access the user ID in a view, you should pass it as a variable from the controller. For example:

public function myMethod()
{
    $user = auth()->user();
    return view('myview', compact('user'));
}

<p>User ID: {{ $user->id }}</p>

In a middleware: If you're trying to access the user ID in a middleware, you should use the $auth property instead of the AuthManager facade. For example:

public function handle($request, Closure $next)
{
    $userId = $this->auth->user()->id;
    // ...
}

By identifying where in your code you're trying to access the non-existent $id property on the AuthManager class, and correcting it by using the appropriate method or property instead, you should be able to resolve the "Undefined property: Illuminate\Auth\AuthManager::$id" error in Laravel 5.5.