Thank you for your reply. Fortunately, clearing the browser history helped with white screens. After getting into the shop kit and turning off Variations swatches, the problem : “Warning: Undefined array key ?rand-ident” in /home/…/ftp/…/wp/wp-content/plugins/kadence-woo-extras/lib/swatches/kt-variations-swatches-output.php on line 262.” disappeared. I previously turned off prompts on my hosting.