Could be a misconfiguration somewhere with the new template you created.
Try duplicating the entire folder /includes/templates/classic and renaming it to /includes/templates/mytemplate.
Next, edit the file /includes/templates/mytemplate/template_info.php as follows:
PHP Code:
<?php
$template_name = 'My Template';
$template_version = 'Version 1.0.0';
$template_author = 'Myself';
$template_description = 'Simple description';
$template_screenshot = 'scr_template_default.jpg';
?>
Next, go to your admin (Tools > Template Selection) and see if you can see the new template with the name "My Template".