I've encountered this error and it was because the id belonged to a media node.
Media is treated differently to other content and there's no easy way of getting the url because different types of media store the url in different ways depending on context. That's why the NiceUrl function doesn't work for media (according to the umbraco developers).
My specific scenario was using images that had been selected using a media picker. I got the url via the following code. I wrapped it up in an extension method so you can consume it from a template in a convenient way.
public static string GetMediaPropertyUrl(this IPublishedContent thisContent, string alias, UmbracoHelper umbracoHelper = null)
{
string url = "";
if (umbracoHelper == null)
umbracoHelper = new UmbracoHelper(UmbracoContext.Current);
var property = thisContent.GetProperty(alias);
string nodeID = property != null ? property.Value.ToString() : "";
if (!string.IsNullOrWhiteSpace(nodeID))
{
//get the media via the umbraco helper
var media = umbracoHelper.TypedMedia(nodeID);
//if we got the media, return the url property
if (media != null)
url = media.Url;
}
return url;
}