Images not rendering

recently I have changed the url

How exactly did you do that?

And what urls are entered in Settings -> General? And – no – do not change them.

Yes – unless you followed the instructions in Changing_The_Site_URL.

I’d actually recommend that you use Method 2 – the functions.php method. In which case, you add the lines suggested for that method right after the opening <?php tag at the top of the file.

No. Just use:

update_option('siteurl','http://example.com');
update_option('home','http://example.com');

Can you post a link to a publically accessible page that includes at least one of these “missing” images?

You have a file/folder permissions problem. Check that anti-hotlinking isn’t enabled in your hosting account. If it is, try disabling it.