Receive the following message when trying to submit a CreateBPRecord:"The given key was not present

The call to CreateBPRecord is consistently returning a, "The given key was not present in the dictionary" message. The code for when the CreateBPRecord is as follows:

                         currentLog.postStringtoLog("Attempting to connect to Unifier web service engine... ");

                        // CONNECT TO UNIFIER WS

                        try

                        {

                            ThisWS = new UnifierWS.UnifierIntWS(CSN, AC, Environment);

                        }

                        catch (Exception exc)

                        {

                            currentLog.postStringtoLog("Failed to connect to Unifier Web Services:" + exc.Message);

                            // SHOW THE FAIL BLOCK

                            failNotice.Visible = true;

                            return;

                        }

                        // POST NEW RESERVATION

                        Dictionary<string, string> postResult = new Dictionary<string, string>();

                        currentLog.postStringtoLog("Successfully connnected to Unifier.\nAttempting to create BP record type " + BPName

                                                    + "...");

                        try

                        {

                            // BPS ARE COMPANY LEVEL SO NULL IS PASSED