Laravel 5.3 Error: ' Creating default object from empty value '

This is the code:

activationservice.php

    
  Mailer = $mailer;        $this->activationrepo = $activationRepo; The Public Function Sendactivationmail ($user) {if ($user->activated | |! $this->shoul            Dsend ($user)) {return;                } $token = $this->activationrepo->createactivation ($user);            $link = route (' User.activate ', $token);                $message = sprintf (' Activate account%s ', $link, $link); $this->mailer->raw ($message, function (message $m) use ($user) {$m->to ($user->email)->subje            CT (' Activation mail ');                }); The Public Function Activateuser ($token) {$activation = $this->activationrepo->getactiva                Tionbytoken ($token);            if ($activation = = = null) {return null;            } $user = User::find ($activation->user_id);            The following line is 53 rows.       $user->activated = true;         $user->save ();                $this->activationrepo->deleteactivation ($token);            return $user; } Private Function Shouldsend ($user) {$activation = $this->activationrepo->getactivati            On ($user); return $activation = = = NULL | |        Strtotime ($activation->created_at) + * $this->resendafter < time (); }        }

Error message:

    ErrorException in ActivationService.php line 53:    Creating default object from empty value

The position of the 53 line is commented in the code, and the code is$user->activated = true;

Problem:
How does the above code resolve this error?

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