Querying WorkItem TFS SDK - timeZone must not be null

Hi,

I'm creating a query using the SDK for Java. 

I want to get the ID regarding the last 2 days.

String wiqlQuery = "Select ID from WorkItems where System.ChangedDate > @Today-2";

I got the following message:

Exception in thread "main" java.lang.NullPointerException: timeZone must not be null

Could anyone help me on that?

Thanks in advance.