Find validateURLScheme function in vendor\magento\framework\Image\Adapter\Gd2.php file at line 96. Replace function with this:
private function validateURLScheme(string $filename) : bool
{
$allowed_schemes = ['ftp', 'ftps', 'http', 'https'];
$url = parse_url($filename);
if ($url && isset($url['scheme']) && !in_array($url['scheme'], $allowed_schemes) && !file_exists($filename))
{
return false;
}
return true;
}