4.6 has crashed my site

I’m so sorry! I read what you wrote but I do not understand how to do this … I got this error: “PHP Fatal error: Can not redeclare the_post_thumbnail_caption () (previously declared in / www / htdocs / XXXX / cms / wp-includes / post- Template.php: 244) in /www/htdocs/XXXX/cms/wp-content/themes/TEMA/functions.php on line 183”

Nowhere in my theme’s function.php did I find “the_post_thumbnail_caption ()” other than in lines 174-183 which look like this:

Function the_post_thumbnail_caption () {
?? Global $ post;

?? $ Thumbnail_id = get_post_thumbnail_id ($ post-> ID);
?? $ Thumbnail_image = get_posts (array (‘p’ => $ thumbnail_id, ‘post_type’ => ‘attachment’));

?? If ($ thumbnail_image && isset ($ thumbnail_image [0])) {
???? Echo ‘<span>’. $ Thumbnail_image [0] -> post_excerpt. ‘</ Span>’;
?? }
}

What am I going wrong?

Many thanks for your help!

Wow thanks Darko for your advice ??