Only initializers, entity members, and entity navigation properties are supported

I'm getting this exception :

The specified type member 'Paid' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported.

    public ActionResult Index()
    {
        var debts = storeDB.Orders
            .Where(o => o.Paid == false)
            .OrderByDescending(o => o.DateCreated);

        return View(debts);
    }

My Model class

public partial class Order
{
    public bool Paid {
        get {
            return TotalPaid >= Total;
        }
    }

    public decimal TotalPaid {
        get {
            return Payments.Sum(p => p.Amount);
        }
    }

Payments is a Related table containing the field amount, The query works if I remove the Where clause showing correct information about the payments, any clue what's wrong with the code?

Solved like the answer suggested with :

    public ActionResult Index()
    {
        var debts = storeDB.Orders
            .OrderByDescending(o => o.DateCreated)
            .ToList()
            .Where(o => o.Paid == false);

        return View(debts);
    }