"Not starting NFS kernel daemon: no exports."

I'm rebuilding a Debian 8.6 server with Ansible. My playbook has always worked until yesterday when one of the tasks that mounts a remote NFS file system would always time out. I'm couldn't figure out the problem so today I'm installing and configuring NFS by hand using these Linode instructions: ~~[https://www.linode.com/docs/networking/basic-nfs-configuration-on-debian-7" target="_blank">](https://www.linode.com/docs/networking/ … n-debian-7">https://www.linode.com/docs/networking/basic-nfs-configuration-on-debian-7](. If I configure both file server and client according to the instructions and run these commands:

sudo service nfs-kernel-server start
sudo service nfs-kernel-server status

I get this message:

Not starting NFS kernel daemon: no exports. ... (warning).

This is the /etc/exports file I've always used. The filesystem does exist on the server and the mount point exists on the client.

/var/www/example.com    <client private="" ip="">/32(rw,no_root_squash,subtree_check)</client>

What else could be causing this message which results in the mount command timing out?