How to fix a null reference exception?

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C#

.NET

.NET4

I currently have a web form that is connected a database. When a user makes an entry and hit the submit form I want to store the values they have entered in each field. I've debugged the code below and can't seem to see where an object reference is not being set to an instance of an object. I've even checked to see the value value is updated with the corresponding user entry.

protected void uxSubmitBtn_Click(object sender, EventArgs e)
{
    var accountTrackerEntrySVC = new AccountTrackerEntrySVC();

    var result = ViewState["AccountEntryID"] == null ?
    accountTrackerEntrySVC.InsertAccountTrackerEntry(//uxAccountNumTxt.Text.Trim(),
    DataConverter.StringToInteger(ViewState["DataCustodianWorkerNum"].ToString()),
    uxDataBeingTransferredDescTxt.Text.Trim(),
    uxPurposeOrFunctionDialInDescTxt.Text.Trim(),
    uxPhysicalLocationTxt.Text.Trim(),
    uxPurposeOrFunctionDialOutDescTxt.Text.Trim(),
    uxApplicationUtilizingModemDescTxt.Text.Trim(),
    uxPasswordChangeFrequencyDescTxt.Text.Trim(),
    uxOtherLayerAuthenticationDescTxt.Text.Trim(),
    uxMachineServerModeConnectionDescTxt.Text.Trim(),
    CommonSVC.GetUserInfoFormattedFromSession(),
    uxTypeOfconnectionDescTxt.Text.Trim()
    ,modemRequirementCB.Checked
    ,ModemConnectionToNetworkDeviceCB.Checked
    ,PasswordProtectedCB.Checked) :
    accountTrackerEntrySVC.UpdateAccountTrackerEntry(DataConverter.StringToInteger(ViewState["AccountEntryID"].ToString()),
    CommonSVC.GetUserInfoFormattedFromSession(),
    uxDataBeingTransferredDescTxt.Text.Trim(),
    uxPurposeOrFunctionDialInDescTxt.Text.Trim(),
    uxPhysicalLocationTxt.Text.Trim(),
    uxPurposeOrFunctionDialOutDescTxt.Text.Trim(),
    uxApplicationUtilizingModemDescTxt.Text.Trim(),
    uxPasswordChangeFrequencyDescTxt.Text.Trim(),
    uxOtherLayerAuthenticationDescTxt.Text.Trim(),
    uxMachineServerModeConnectionDescTxt.Text.Trim(),
    uxTypeOfconnectionDescTxt.Text.Trim(),
    modemRequirementCB.Checked,
    ModemConnectionToNetworkDeviceCB.Checked,
    PasswordProtectedCB.Checked);

    if (result.Successful)
    {
        uxInfoMsg.DisplayMessage(result.Message, InfoMessage.InfoMessageType.Success);
    }
    else
    {

    }
    //Hide progress indicator
    Master.HideProgressIndicator();
}

Perhaps another pair of eyes will see the error I have yet to spot. Still fairly new to c# so I'll do my best to post responses to any questions you may have. Thanks!