Find validateURLScheme function in vendor\magento\framework\Image\Adapter\Gd2.php file. at line 96. Replace function with this
if ($url && isset($url['scheme']) && !in_array($url['scheme'], $allowed_schemes) && !file_exists($filename)) {
return false;
}
Including issue: https://www.polacin.com/magento2/fix-issues-when-install-magento-2-3-0-on-xampp/
