CRM 2011 Bulk Create Error

Hi,

I tried creating multiple records at a time but got   error. I am using sdk sample but it doesn't work perfectly. Below is the  error detail.--

The formatter threw an exception while trying to deserialize the message: There was an error while trying to deserialize parameter http://schemas.microsoft.com/xrm/2011/Contracts/Services:request. The InnerException message was 'Error in line 1 position 11790. Element 'http://schemas.microsoft.com/xrm/2011/Contracts/Services:request' contains data from a type that maps to the name 'http://schemas.microsoft.com/xrm/2011/Contracts:ExecuteMultipleRequest'. The deserializer has no knowledge of any type that maps to this name. Consider changing the implementation of the ResolveName method on your DataContractResolver to return a non-null value for name 'ExecuteMultipleRequest' and namespace 'http://schemas.microsoft.com/xrm/2011/Contracts'.'.  Please see InnerException for more details.

Any help will be appreciated.

Thanks,

Abhishek

Abhishek