When configuring laravel project:

First of all, there is no vendor directory for the clone project from GitHub,

Run composer install to get composer dependencies from composer.json

Error running project:

1.Whoops, looks like something went wrong.

Create a new. Env file, refer to. Env. Example

Modification: app_ DEBUG=true

2.APP_ The value of key

No supported encrypter found. The cipher and/or key length are invalid.

Run in the project directory to get the new app_ KEY：

php artisan key:generate

OK !