kaiyakai on "[Plugin: Polylang] Warning: Illegal string offset 'taxonomy' error!"

Thanks for reply, the code as below:
// to avoid conflict beetwen taxonomies
// FIXME generalize post format like taxonomies (untranslated but filtered)
$has_tax = false;
if (isset($query->tax_query->queries))
foreach ($query->tax_query->queries as $tax)
if( is_array( $tax ) && array_key_exists( 'taxonomy', $tax ) ) {
if ('post_format' != $tax['taxonomy'])
$has_tax = true;
}