Update InterviewPolicy.php

app/Policies/InterviewPolicy.php

@@ -50,7 +50,7 @@ class InterviewPolicy
      */
     public function create(User $user, $study)
     {
-        if (! $user->can('create-interviews', Study::where('id', '=', $study)->first()->name)) {
+        if (! $user->can('create-interviews', Study::where('id', '=', $study)->first()->id)) {
             abort(403, 'You are not allowed to create interviews for this study');
         }