Some users are experiencing an error after upgrading. The error shown is: No supported encrypter found. The cipher and / or key length are invalid.

This error relates to the configuration setting found in the file config/app.php. Under the section Encryption Key you should find two entries called key and cipher. If these entries are missing then they should be added to the file.

/*
|--------------------------------------------------------------------------
| Encryption Key
|--------------------------------------------------------------------------
|
| This key is used by the Illuminate encrypter service and should be set
| to a random, 32 character string, otherwise these encrypted strings
| will not be safe. Please do this before deploying an application!
|
*/

'key' => 'CHANGE_ME!!!!!!!!!!!!!!!!!!!!!!',

'cipher' => 'AES-256-CBC',

In some cases the key may not be an appropriate length, it should either be 16 or 32 characters depending on the cipher used:

• AES-256-CBC should use a 32 character length key.
• AES-128-CBC should use a 16 character length key.

Following the instructions above should remedy the situation.