Here in Papion headquarters we love using ACF.
Advanced Custom Fields is one of the best WordPress plugins for custom field management.
Recently, with the new WordPress 4.8.3, a change was made in the prepare query to the database.
Instead of characters like % now we have placeholders like {1872368126381726387126381276381726318723} (for more information see code).
It does not involve any major issues, except when we use ACF in combination with get_posts and metaquery to search for post based on repeater fields that have meta_key in fieldgrup_%_field format like “fieldgrup_0_field”, “fieldgrup_1_field”, etc.
One of the solutions ACF proposes is (source)
function my_posts_where( $where ) {
$where = str_replace("meta_key = 'locations_%", "meta_key LIKE 'locations_%", $where);
return $where;
}
add_filter('posts_where', 'my_posts_where');
However, with the update, instead of the “%” character, we find ourselves with a numeric placeholder, so this code should be changed so that the comparison is done with the query without placeholders:
function my_posts_where( $where ) {
$where = str_replace("meta_key = 'locations_%", "meta_key LIKE 'locations_%", $where);
return $where;
}
add_filter('posts_where', 'my_posts_where');
Una delle cose che spesso fa un po’ scervellare è la scelta 
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