Twig/Environment.php Warning - filemtime(): stat failed

I am using my LEMP web stack with Nginx 1.9.2, PHP 5.6.10 w/Zend Opcache + MariaDB 10.0.20 with CSF Firewall.

When I install from the marketplace, I get errors like below, however the install seems to go through and reports successfull ?

WARNING: /piwik/vendor/twig/twig/lib/Twig/Environment.php(334): Warning - filemtime(): stat failed for /piwik/tmp/templates_c/99/42/9b36ddfe2c9707c1a3316e07400ccf5db939d442908f118740eaa6f8f7fd.php - Piwik 2.13.1 - Please report this message in the Piwik forums: (please do a search first as it might have been reported already)

ls -lah piwik/vendor/twig/twig/lib/Twig/Environment.php 
-rw-r--r-- 1 nginx nginx 38K Jun 27 07:48 piwik/vendor/twig/twig/lib/Twig/Environment.php

ls -lah /piwik/tmp/templates_c/99/42/9b36ddfe2c9707c1a3316e07400ccf5db939d442908f118740eaa6f8f7fd.php

-rw-r--r-- 1 nginx nginx 1002 Jun 27 08:03 /piwik/tmp/templates_c/99/42/9b36ddfe2c9707c1a3316e07400ccf5db939d442908f118740eaa6f8f7fd.php

php -i | egrep 'open_basedir|safe'
open_basedir => no value => no value
sql.safe_mode => Off => Off