'templates_c' Directory Permissions

The templates_c subdirectory in the themes/engines/smarty directory must be both readable and writable by the web server process.

In an *nix environment the solution is such:

If you have chown access:

The directory should be owned by your user and have group ownership including your web server process. i.e. (your user name):apache
The directory should be readable/writable/executable for both owner and group and read/execute for other. i.e. 775
If 'apache' is not the correct web server user/group you can check the output of <?php phpinfo(); ?> to find it.

chmod 775 templates_c
chown (your user name):apache templates_c

More likely - no chown access:

A simple
chmod 777 templates_c
will correct the permissions for the directory.

If chown access is available, use it. Not having global write access is preferable but in many cases it's necessary.

In win32 you must give write permissions for the web server process user to the templates_c subdirectory.