Where has my main navigation gone?

If you logon to your website and notice your navigation has disappeared from the top of the page like so: 

The dont panic! It's easily fixable with the click of a button. 

Navigate to Appearance > Menus in the Wordpress dashboard: 

Once you've accessed your menu pleas select 'Primary Navigation' from the dropdown like so:

You'll then see this page:

In the 'Menu Settings' area you'll see two checkboxes next to 'Display Location' click the 'Primary Navigation' checkbox like so:

Then click 'Save Menu' 

This will restore your primary navigation to it's rightful place.