I am using the W3 Total Cache plugin on a multi site WordPress install.
For some reason I the "Set expires header" option, in browser settings is disabled. I cannot click on the checkbox to enable it.
I've made sure mod_expires is enabled, and in .htaccess I made the edit below but still that checkbox will not become enabled so I can click it.
<ifmodule mod_expires.c> ExpiresActive on </ifmodule>
Any help pointing me in the right direct would be appreciated.