Omitted to add to my above post:
For testing purposes you also need to make this change in your existing file YOUR_ADMIN/includes/modules/sitemapxml_install.php (around line 14):
or else you are getting prompted to install/upgrade over and over again........PHP Code:
//$current_version = '3.6 26.04.2016 10:33:09';
$current_version = '3.6.1';
Sorry about that.
Frank