HTTP Error: 500 Internal_Server_Error on PHP5

I’m going through the OpenFire wizard on first setup. I’ve got through connecting to our LDAP server and at the end of the group mapping step I’m presented with the following error:

“HTTP ERROR: 500 INTERNAL_SERVER_ERROR”.

I’ve installed OpenFire on Ubuntu 14.04 and I’m using the latest PHP5. I found a post (from a few years back - https://shyju.wordpress.com/tag/http-error-500-internal_server_error/)) that says to issue the following instructions to fix this problem:

# mkdir /var/lib/php/session/cache # chmod 777 cache

Problem is this blog post was for an older version of PHP so the location they reference isn’t available to me. What would be the fix for my recent version of PHP to get around this error?

Thank you.