错误403 Drupal 7中找不到图像

I create a block from configuration. Inside this block, I write this code...

 <div class="provider-bg" id="provider1">
      <img alt="" class="img-responsive" src="<?php echo base_path().path_to_theme() ?>/images/provider-1.jpg" />
 </div>

Then, I save with PHP in text format.

My virtual host is ... http://localhost:8888/drupal
So, the image path will be like this ...

<img alt="" src="/drupal/sites/all/themes/myancast/images/ios.png">

This image appears in the last few days ago. Today, I run the site and that image disappear immediately and got 403 error.

Failed to load resource: the server responded with a status of 403 (Forbidden).
I'm trying to find the solution the whole day. But, I still cannot solve.
Can anyone help me please ?

Add global $base_url in your code and use like below

<img alt="" class="img-responsive" src="<?php echo $base_url.'/'.path_to_theme(); ?>/images/provider-1.jpg" />

did you try this ?

<img alt="" class="img-responsive" src="<?php echo '/'.path_to_theme(); ?>/images/provider-1.jpg" />

try this,

<?php
 $imgurl = file_create_url(path_to_theme().'/images/provider-1.jpg');
?>
<img alt="" class="img-responsive" src="<?php echo $imgurl ?>"/>

</div>