Hello
I recently upgraded from PHP 5.6 to 7.0.   After the upgrade I get the following error.  I didn't touch any permissions within apache or any of the folders.  I just strictly updated PHP.  Any thoughts on why I would be getting this error?

./_data/templates_c no write access

#1    mkgetdir /home/www/public_html/include/template.class.php(116)
#2    Template::__construct /home/www/public_html/include/common.inc.php(233)
#3    include_once /home/www/public_html/index.php(26)


Piwigo version: 2.9.3
PHP version:  7.0.30
MySQL version: mysql  Ver 15.1 Distrib 5.5.56-MariaDB,
Piwigo URL: http://