Dotenv must be an instance of Dotenv\Loader

Ok so changing that hook to this seems to be working, I am not entirely sure it's the correct approach but digging into the library code seems ok.

$hook['pre_system'] = function() {    $dotenv = Dotenv\Dotenv::create(__DIR__);    $dotenv->load();}

If this is wrong for any reason please let me know. Thanks

I tried all solutions then I found that my version of phpdotenv was 4.x.x. For those who have a confusion of why the solutions above doesn't work.

Here is the new way to load the env with path as the constructor param:

$dotenv = Dotenv\Dotenv::createImmutable(__DIR__.'/..');$dotenv->load();

Dotenv must be an instance of Dotenv\Loader

Actually you are not following documentation of upgrading Laravel from any version to 5.8, I have found solution after searching of few hours. Finally i found the solution. You just need to replace this code in your environment file.

$env = $app->detectEnvironment(function(){$environmentPath = __DIR__.'/../.env';$setEnv = trim(file_get_contents($environmentPath));if (file_exists($environmentPath)){    putenv('APP_ENV='.$setEnv);    if (getenv('APP_ENV') && file_exists(__DIR__.'/../.' .getenv('APP_ENV') .'.env')) {        $dotenv = Dotenv\Dotenv::create(__DIR__.'/../', '.'.getenv('APP_ENV').'.env');        $dotenv->overload();    }}});

Here is a link where you can check in details how to use multiple env files in laravel 5.8. Reference Link

Enjoy the coding . . . !!!