I detect it is Raindrops Bug
Thank you for pointing out.
I will fixed next version Raindrops.
Quick Fix below
Open functions.php and add page first
<?php
/*------------- add codes start-----------------*/
if ( !function_exists( 'raindrops_heading_image_validate' ) ) {
function raindrops_heading_image_validate( $input ) {
if ( preg_match( '/[^(a-z|0-9|_|-|\.)]+/si', $input ) ) {
return raindrops_warehouse_clone( 'raindrops_heading_image' );
}
return $input;
}
}
if ( !function_exists( 'raindrops_footer_image_validate' ) ) {
function raindrops_footer_image_validate( $input ) {
global $raindrops_options;
if ( preg_match( '/[^(a-z|0-9|_|-|\.)]+/si', $input ) ) {
return raindrops_warehouse_clone( 'raindrops_footer_image' );
}
return $input;
}
}
if ( !function_exists( 'raindrops_header_image_validate' ) ) {
function raindrops_header_image_validate( $input ) {
if ( preg_match( '/[^(a-z|0-9|_|-|\.)]+/si', $input ) ) {
return raindrops_warehouse_clone( 'raindrops_header_image' );
}
return $input;
}
}
/*------------- add codes end-----------------*/
/**
* functions and constants for Raindrops theme
*
*
* @package Raindrops
* @since Raindrops 0.1
*/
if ( !defined( 'ABSPATH' ) ) {
exit;
}
Thank you.
@rburtoff
Sorry my mistake