What are the common mistakes to avoid when working with encrypted arrays in PHP?

One common mistake to avoid when working with encrypted arrays in PHP is not properly serializing and encrypting the array before storage or transmission. To solve this issue, you should serialize the array using `serialize()` before encrypting it, and then decrypt and unserialize it using `unserialize()` after decryption.

// Encrypt and serialize the array
$encryptedData = openssl_encrypt(serialize($myArray), 'AES-256-CBC', $encryptionKey, 0, $iv);

// Decrypt and unserialize the array
$decryptedData = unserialize(openssl_decrypt($encryptedData, 'AES-256-CBC', $encryptionKey, 0, $iv));