Topic: Product error

Hi, when I add a product,
bottom of the product page take an error.

ERROR IS;

( ! ) Warning: A non-numeric value encountered in C:\wamp64\www\rumanli\wp-content\plugins\woocommerce\includes\wc-product-functions.php on line 912
Call Stack
# Time Memory Function Location
1 0.0001 408160 {main}( ) …\index.php:0
2 0.0001 408448 require( ‘C:\wamp64\www\rumanli\wp-blog-header.php’ ) …\index.php:17
3 1.9958 22075264 require_once( ‘C:\wamp64\www\rumanli\wp-includes\template-loader.php’ ) …\wp-blog-header.php:19
4 2.0059 22177312 include( ‘C:\wamp64\www\rumanli\wp-content\themes\xstore\woocommerce\single-product.php’ ) …\template-loader.php:74
5 2.2858 26737056 wc_get_template_part( ) …\single-product.php:33
6 2.2866 26737168 load_template( ) …\wc-core-functions.php:181
7 2.2873 26737720 require( ‘C:\wamp64\www\rumanli\wp-content\themes\xstore\woocommerce\content-single-product.php’ ) …\template.php:690
8 2.4411 26862592 woocommerce_output_related_products( ) …\content-single-product.php:131
9 2.4411 26862592 woocommerce_related_products( ) …\wc-template-functions.php:1808
10 2.4574 26873712 wc_get_template( ) …\wc-template-functions.php:1845
11 2.4581 26874344 include( ‘C:\wamp64\www\rumanli\wp-content\themes\xstore\woocommerce\single-product\related.php’ ) …\wc-core-functions.php:211
12 2.4581 26874368 wc_get_related_products( )

This is problem, but I couldn’t screenshot, how can I do this ?