There are several edm-namespaces for various OData versions. I'd first try to avoid the --v switch and let JaySvcUtil.exe trying to determine the correct one.
If that doesn't work check the supported version of name-spaces at https://github.com/jaydata/JaySvcUtil/blob/master/Program.cs
public static Dictionary<string, string> NamespaceVersions = new Dictionary<string,string>
{
{"http://schemas.microsoft.com/ado/2007/05/edm", "V11" },
{"http://schemas.microsoft.com/ado/2006/04/edm", "V1" },
{"http://schemas.microsoft.com/ado/2008/09/edm", "V2" },
{"http://schemas.microsoft.com/ado/2009/08/edm", "V21" },
{"http://schemas.microsoft.com/ado/2009/11/edm", "V3" }
};
If the one that is produced by localhost:1578/Service.svc/$metadata is not in there add an request at https://github.com/jaydata/JaySvcUtil/issues