TokenMismatchException for particular post url

can you post the code for the form leading to this issue?

@mushood In blade.php

     @if($mode=='add')
         <form class="form-horizontal" role="form" action="/customattributevalue/add" method="post">
     @elseif($mode=='edit')
        <form class="form-horizontal" role="form" action="/customattributevalue/edit" method="post">
        @endif
           <div class="form-group">
              <label for="custom_attribute_name" class="col-sm-2 control-label">Custom Attribute Name</label>
              <div class="col-sm-10">
              <select class="form-control" id="custom_attribute_id" name="custom_attribute_id"> 
                 @foreach($custom_attributes as $custom_attribute)
                 @if($mode=='add')
                 <option value="{{ $custom_attribute->custom_attribute_id }}">
             @elseif($mode=='edit')
             <option value="{{ $custom_attribute->custom_attribute_id }}" @if($custom_attribute->custom_attribute_id==$custom_attribute_value->custom_attribute_id) selected @endif>
             @endif
             {{ $custom_attribute->custom_attribute_name }}</option>
             @endforeach
             </select>
              </div>
           </div>
           <div class="form-group">
              <label for="custom_attribute_value" class="col-sm-2 control-label">Custom Attribute Value</label>
              <div class="col-sm-10">
                 @if($mode=='add')
                 <input type="text" class="form-control" id="custom_attribute_value" name="custom_attribute_value" value="" placeholder="Custom Attribute Value" maxlength="255"/>
             @elseif($mode=='edit')
             <input type="hidden" name="_token" value="{{ csrf_token() }}"/>
             <input type="hidden" name="custom_attribute_value_id" value="{{ $custom_attribute_value->custom_attribute_value_id }}"/>
             <input type="text" class="form-control" id="custom_attribute_value" name="custom_attribute_value" maxlength="255" value="{{ $custom_attribute_value->custom_attribute_value }}"/>
             @endif
              </div>
           </div>
           <div class="form-group">
              <label for="custom_attribute_value_code" class="col-sm-2 control-label">Custom Attribute Value Code</label>
              <div class="col-sm-10">
                 @if($mode=='add')
                 <input type="text" class="form-control" id="custom_attribute_value_code" maxlength="2" name="custom_attribute_value_code" placeholder="Custom Attribute Value Code"/>
             @elseif($mode=='edit')
             <input type="text" class="form-control" id="custom_attribute_value_code" name="custom_attribute_value_code" placeholder="Custom Attribute Value Code" value="{{ $custom_attribute_value->custom_attribute_value_code }}" maxlength="2" readonly/>
             @endif
              </div>
        </div>
           <div class="form-group">
              <label for="custom_attribute_sizechart_value" class="col-sm-2 control-label">IND Custom Attribute Sizechart Value</label>
              <div class="col-sm-10">
                 @if($mode=='add')
                 <input type="text" class="form-control" id="custom_attribute_sizechart_value" name="custom_attribute_sizechart_value" placeholder="IND Custom Attribute Sizechart Value"/>
             @elseif($mode=='edit')
             <input type="text" class="form-control" id="custom_attribute_sizechart_value" name="custom_attribute_sizechart_value" placeholder="IND Custom Attribute Sizechart Value" value="{{ $custom_attribute_value->custom_attribute_sizechart_value }}"/>
             @endif
              </div>
         </div>
         <div class="form-group">
              <label for="USA_custom_attribute_sizechart_value" class="col-sm-2 control-label">USA Custom Attribute Sizechart Value</label>
              <div class="col-sm-10">
                 @if($mode=='add')
                 <input type="text" class="form-control" id="USA_custom_attribute_sizechart_value" name="USA_custom_attribute_sizechart_value" placeholder="USA Custom Attribute Sizechart Value"/>
             @elseif($mode=='edit')
             <input type="text" class="form-control" id="USA_custom_attribute_sizechart_value" name="USA_custom_attribute_sizechart_value" placeholder="USA Custom Attribute Sizechart Value" value="{{ $custom_attribute_value->custom_attribute_us_sizechart_value}}"/>
             @endif
              </div>
         </div>
           <div class="form-group">
              <div class="col-sm-offset-2 col-sm-10">
                 <button type="submit" class="btn btn-primary">Save Custom Attribute Value</button>
              </div>
           </div>
        </form>

and in controller

public function addCustomAttributeValueGet(Request $request)
{
    $custom_attributes = CustomAttributeMaster::getList();
    
    $header = View::make('header', [])->render();
    $footer = View::make('footer', [])->render();

    $sidebar = View::make('sidebar', [])->render();
    
    $body = View::make(
        'masters.customattributevalue.detail',
        [
            'sidebar'=>$sidebar,
            'mode'=>'add',
            'custom_attributes' => $custom_attributes
        ]
    )->render();

    return response($header.$body.$footer);
}

From here

@elseif($mode=='edit')
             <input type="hidden" name="_token" value="{{ csrf_token() }}"/>

It means that only the mode is edit that you have the csrf token. When the mode is add, you dont have it.

So at the top itself, i would do this

     @if($mode=='add')
         <form class="form-horizontal" role="form" action="/customattributevalue/add" method="post">
     @elseif($mode=='edit')
        <form class="form-horizontal" role="form" action="/customattributevalue/edit" method="post">
        @endif 

             <input type="hidden" name="_token" value="{{ csrf_token() }}"/>

//form continues

Thanks a lot @mushood how do i miss that ???