相同的问题，三天后找到解决方案，并且它可以正常工作. 我的用户模型是:

Same problem, after 3 days find solution and I it working. My User model is:

namespace app\models;

use Yii;
class User extends \yii\db\ActiveRecord implements \yii\web\IdentityInterface
{
    public $username;

    /**
     * @inheritdoc
     */
    public static function tableName()
    {
        return 'tbl_users';
    }

    /**
     * @inheritdoc
     */
    public function rules()
    {
        return [
            [['name', 'email', 'password'], 'required'],
            [['email'], 'unique'],
            [['role', 'status'], 'integer'],
            [['created', 'last_update'], 'safe'],
            [['name', 'email', 'password'], 'string', 'max' => 250]
        ];
    }

    /**
     * @inheritdoc
     */
    public function attributeLabels()
    {
        return [
            'id' => 'ID',
            'name' => 'Name',
            'email' => 'Email',
            'password' => 'Password',
            'role' => 'Role',
            'status' => 'Status',
            'created' => 'Created',
            'last_update' => 'Last Update',
        ];
    }
    public function getAuthKey() {

    }

    public function getId() {
        return $this->id;
    }

    public function validateAuthKey($authKey) {

    }

    public static function findIdentity($id) {

    }

    public static function findIdentityByAccessToken($token, $type = null) {

    }
    public static function findByEmail($email)
    {
        return static::findOne(array('email'=>$email));
    }

    public function validatePassword($password)
    {
        return $this->password === $password;
    }
}

我更改:

public static function findIdentity($id) {

}

收件人:

public static function findIdentity($id) {
    return self::findOne(array('id'=>$id));
}

对我有用.