Don't validate cell against previous value before it has a previous value
Don't validate cell against previous value before it has a previous value

jeoffman/EDDiscovery,vendolis/EDDiscovery,mwerle/EDDiscovery,jgoode/EDDiscovery,jgoode/EDDiscovery,jthorpe4/EDDiscovery,mwerle/EDDiscovery,jeoffman/EDDiscovery,vendolis/EDDiscovery