SearchByCriteria Exception

SearchByCriteria Exception

Hi
I am getting an exception when I use SearchByCritera.

ZCRMSDK.CRM.Library.CRMException.ZCRMException: 'Exception of type 'ZCRMSDK.CRM.Library.CRMException.ZCRMException' was thrown.'
I am using c# SDK
  1. var accountModule = ZCRMModule.GetInstance("Accounts");
                BulkAPIResponse<ZCRMRecord> response = accountModule.SearchByCriteria("(Account_Name:equals:" + HttpUtility.UrlEncode(companyName) + ")");