Trying to Move Cards - manatee.trello

Question

I am trying to move a card I have found using the search function from one list to another on the same board.
I have tried to set up a new list using the a new factory.list and searching for the list using FirstorDefault LINQ Query but keep getting an Error.
Below is some code I have tried to move my cards.
string query = jnum;
var search = factory.Search(query, 1, SearchModelType.Cards, new IQueryable[] { board });
await search.Refresh();
var CardList = search.Cards.ToList();
foreach (var card in CardList)
{
string tName = card.Name.Substring(0, 6);
if (tName == jnum.Trim())
{
cardid = card.Id;
}
}
var FoundCard = factory.Card(cardid);
string FoundListid = FoundCard.List.Id;
var fromlist = factory.List(FoundListid);
if (Item != null)
{
if (mail.Body.ToUpper().Contains("Approved for Print".ToUpper()))
{
//var ToList = factory.List("5db19603e4428377d77963b4");
var ToList = board.Lists.FirstOrDefault(l => l.Name == "Signed Off");
FoundCard.List = ToList;
// from on proof
//MessageBox.Show("Approved for Print");
}
else if (mail.Body.ToUpper().Contains("Awaiting Review".ToUpper()))
{
//var ToList = factory.List("5db19603e4428377d77963b3");
var ToList = board.Lists.FirstOrDefault(l => l.Name == "On Proof");
FoundCard.List = ToList;
// from in progress or to start
// MessageBox.Show("Awaiting Review");
}
else if (mail.Body.ToUpper().Contains("Amends".ToUpper()))
{
var ToList = factory.List("5dc9442eb245e60a39b3d4a7");
FoundCard.List = ToList;
// from on proof
//MessageBox.Show("Amends");
}
else
{
// non job mail
}
}
I keep getting a is not a valid value Error.
Thanks for help