I\'m using Laravel 5.0 for all my projects. Yesterday, I\'ve updated my PHP version from 7.0.x to version 7.1.0. Once updated, I tried opening my Laravel project and saw thi
This error occurs because you probably have something other than AES-256-CBC as your cipher in your config/app.php file that depends on the mcrypt extension. Perhaps you are using MCRYPT_RIJNDAEL_256 or MCRYPT_RIJNDAEL_128?
The best thing you can do without a full-blown Laravel upgrade is install the legacy encrypter and use it to update all your encrypted data to use the AES-256-CBC cipher which has been the default cipher since Laravel 5.1, I believe. Once you do this, you should be able to use PHP 7.1 for your Laravel application.