'htmlentities() expects parameter 1 to be string, array given' error on Laravel view

I was testing the Request.php (submitting form with empty required fields) of my create view, and got the 'htmlentities() expects parameter 1 to be string, array given' error.

I know the error was generated because of the code below. This is a part of my view (calls javascript functions) used to create future appointment reminders.

I just don't see what is causing the error exactly.

<div style="display:none">    
<div id="reminderiteminitial">      
<div class="row" style="padding: 0.5em 0 0.5em 0.5em">  
      <div class="col-sm-2" >
           {!! Form::text('reminder_time[]', 30, ['class' => 'form-control', 'placeholder' => '']) !!}
      </div>
      <div class="col-sm-2" >
           {!! Form::select('reminder_timeunit[]', ['minute' => 'minutes(s)', 'hour' => 'hour(s)', 'day' => 'day(s)', 'week' => 'week(s)', 'month' => 'month(s)'], null, ['class' => 'form-control']) !!}
      </div>
      <div class="col-sm-2" >
           {!! Form::select('delivery_method[]', ['eml' => 'Email'], null, ['class' => 'form-control']) !!}
      </div>
      <div class="col-sm-4" >
           {!! Form::text('delivery_contact[]', null, ['class' => 'form-control', 'placeholder' => 'Your email address']) !!}
      </div>
      <div class="col-sm-2" >
          <input class="btn btn-default" type="button" value="Delete reminder" onClick="removeitem(this);">
      </div>

</div>
</div>
</div>

<div id="reminderitem">     
</div>

<div class="row" style="padding: 1.5em 0 2.5em 0">      
<div class="col-sm-12">         
      <input class="btn btn-default" type="button" value="Add a reminder" onClick="addreminderitem();">
</div>
</div>  

via Chebli Mohamed