Prestashop 1.6 checkout error 'Undefined index: awp_url_rewrite' and 'Trying to get property of non-object '

[Cassandra_]

Customers at checkout cannot go on and have this message displayed:

Notice: Undefined index: awp_url_rewrite in /var/www/vhosts/katanamart.de/httpdocs/tools/smarty/sysplugins/smarty_internal_templatebase.php(157) : eval()'d code on line 52

Notice: Trying to get property of non-object in /var/www/vhosts/katanamart.de/httpdocs/tools/smarty/sysplugins/smarty_internal_templatebase.php(157) : eval()'d code on line 52

I have disabled cache and forced compilation.

[endriu107]

Turn off debug mode then this notice shouldn't be visible.