one user reported this ,"into /check-email/assets/vendor/jquery-ui/themes/base/jquery-ui.min.css file there’s references to an images folder (ex. “.ui-icon{background-image:url(“images/ui-icons_444444_256x240.png”)}” but images folder doesn’t exist. I fixed with a simple upload direclty from https://jqueryui.com/download/#!version=1.12.1 (base theme)."
one user reported this ,"into /check-email/assets/vendor/jquery-ui/themes/base/jquery-ui.min.css file there’s references to an images folder (ex. “.ui-icon{background-image:url(“images/ui-icons_444444_256x240.png”)}” but images folder doesn’t exist. I fixed with a simple upload direclty from https://jqueryui.com/download/#!version=1.12.1 (base theme)."
reference ticket: https://wordpress.org/support/topic/images-folder-missing-for-jquery-ui-min-css/