I have found in the PHP log the error (many times) - when it starts seems to match when my website does not work anymore;
PHP Fatal error: Can't use method return value in write context in /home/gqowpzrh/public_html/lbc/lib/plugins/odt/helper/config.php on line 569
And when I go and see at config.php of the ODT plugin at line 569 I find;
if (!empty($this->getParam ('template')) && empty($this->getParam ('odt_template'))) {