[Solved] Laravel: The only supported ciphers are AES-128-CBC and AES-256-CBC with the correct key lengths.

Recently I set up a project with the laravel PHP framework and hit a little bump right away. After cloning my project on my computer at home, I encountered an error message about the AES key length.

Luckily I wasn't the only one with that issue and running the following and conveniently available artisan commands fixed it already:

php artisan key:generate
php artisan config:clear

Commands with output:

php artisan key:generate
Application key [base64:xxxxxxxxxxxxxx] set successfully.
php artisan config:clear
Configuration cache cleared!

The project had a basic authentication setup through php artisan make:auth by the way, which is why it needs sessions in the first place.

Full error messages below:

RuntimeException in compiled.php line 13261:
The only supported ciphers are AES-128-CBC and AES-256-CBC with the correct key lengths.
in compiled.php line 13261
at Encrypter->__construct('', 'AES-256-CBC') in compiled.php line 7739
at EncryptionServiceProvider->Illuminate\Encryption\{closure}(object(Application), array()) in compiled.php line 1374
at Container->build(object(Closure), array()) in compiled.php line 1330
at Container->make('encrypter', array()) in compiled.php line 1908
at Application->make('Illuminate\Contracts\Encryption\Encrypter') in compiled.php line 1431
at Container->resolveClass(object(ReflectionParameter)) in compiled.php line 1408
at Container->getDependencies(array(object(ReflectionParameter)), array()) in compiled.php line 1394
at Container->build('App\Http\Middleware\EncryptCookies', array()) in compiled.php line 1330
at Container->make('App\Http\Middleware\EncryptCookies', array()) in compiled.php line 1908
at Application->make('App\Http\Middleware\EncryptCookies') in compiled.php line 9868
at Pipeline->Illuminate\Pipeline\{closure}(object(Request)) in Pipeline.php line 33
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in compiled.php line 9858
at Pipeline->then(object(Closure)) in compiled.php line 8164
at Router->runRouteWithinStack(object(Route), object(Request)) in compiled.php line 8155
at Router->dispatchToRoute(object(Request)) in compiled.php line 8146
at Router->dispatch(object(Request)) in compiled.php line 2472
at Kernel->Illuminate\Foundation\Http\{closure}(object(Request)) in Pipeline.php line 53
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in compiled.php line 3224
at CheckForMaintenanceMode->handle(object(Request), object(Closure)) in compiled.php line 9873
at Pipeline->Illuminate\Pipeline\{closure}(object(Request)) in Pipeline.php line 33
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in compiled.php line 9858
at Pipeline->then(object(Closure)) in compiled.php line 2416
at Kernel->sendRequestThroughRouter(object(Request)) in compiled.php line 2400
at Kernel->handle(object(Request)) in index.php line 54
at require_once('/home/jonathan/projects/xxx/xxx-backend/public/index.php') in server.php line 21 in compiled.php line 13261
at Encrypter->__construct('', 'AES-256-CBC') in compiled.php line 7739
at EncryptionServiceProvider->Illuminate\Encryption\{closure}(object(Application), array()) in compiled.php line 1374
at Container->build(object(Closure), array()) in compiled.php line 1330
at Container->make('encrypter', array()) in compiled.php line 1908
at Application->make('Illuminate\Contracts\Encryption\Encrypter') in compiled.php line 1431
at Container->resolveClass(object(ReflectionParameter)) in compiled.php line 1408
at Container->getDependencies(array(object(ReflectionParameter)), array()) in compiled.php line 1394
at Container->build('App\Http\Middleware\EncryptCookies', array()) in compiled.php line 1330
at Container->make('App\Http\Middleware\EncryptCookies', array()) in compiled.php line 1908
at Application->make('App\Http\Middleware\EncryptCookies') in compiled.php line 2426
at Kernel->terminate(object(Request), object(Response)) in index.php line 58
at require_once('/home/jonathan/projects/xxx/xxxx-backend/public/index.php') in server.php line 21