You might get this error message when importing a theme demo:

Maximum execution time of 29 seconds exceeded in /xxxxxx/wp-includes/class-wp-image-editor-imagick.php on line XXX

Solution: Add this piece of code in your child theme’s function.php:

add_filter( 'wp_image_editors', 'change_graphic_lib' );
function change_graphic_lib($array) {
return array( 'WP_Image_Editor_GD', 'WP_Image_Editor_Imagick' );
}