reference# is some numbers-% not clean int,
validation 100% but import 0% and no message at all what's wrong.
PS 1.7.5.0
Use product reference as key->No
Force all ID numbers->No

dev.log
[2019-11-09 18:41:13] php.CRITICAL: Uncaught Exception: An exception has been thrown during the rendering of a template ("Unable to load template 'file:layout-ajax.tpl'"). {"exception":"[object] (Twig_Error_Runtime(code: 0): An exception has been thrown during the rendering of a template (\"Unable to load template 'file:layout-ajax.tpl'\"). at /data01/xx/domeenid/www.xxx.xx/htdocs/p/src/PrestaShopBundle/Resources/views/Admin/layout.html.twig:34, SmartyException(code: 0): Unable to load template 'file:layout-ajax.tpl' at /data01/xx/domeenid/www.xxx.xx/htdocs/p/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php:195)"} [] [2019-11-09 18:41:13] request.CRITICAL: Uncaught PHP Exception Twig_Error_Runtime: "An exception has been thrown during the rendering of a template ("Unable to load template 'file:layout-ajax.tpl'")." at /data01/xx/domeenid/www.xxx.xx/htdocs/p/src/PrestaShopBundle/Resources/views/Admin/layout.html.twig line 34 {"exception":"[object] (Twig_Error_Runtime(code: 0): An exception has been thrown during the rendering of a template (\"Unable to load template 'file:layout-ajax.tpl'\"). at /data01/xx/domeenid/www.xxx.xx/htdocs/p/src/PrestaShopBundle/Resources/views/Admin/layout.html.twig:34, SmartyException(code: 0): Unable to load template 'file:layout-ajax.tpl' at /data01/xx/domeenid/www.xxx.xx/htdocs/p/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php:195)"} []