How to handle error "Exception has been thrown by the target of invocation" in Linq processing
===

Here is my failing code

    var q = (from x in query
    	where x.CustomerID == c.Id
    	where x.Date > date && x.Date < date.AddMonths(1)
    	select x.Price);
    try {
    	j++;
    	List<int> qq = q.ToList();

Last line fails with "Exception has been thrown by the target of invocation" Additional information: Exception has been thrown by the target of an invocation.

query is another linq and in total it's WCF Data client to Server (Entity) application full source file is [Here, on GitHub][1]

How can I understand / handle this issue? other linq queries there work fine

*thank you*

  [1]: https://github.com/Nensha/ENT/blob/master/ENT_Client/MainForm.cs