in two parallel email approval steps

one of the flow (2nd flow) always report error at activity Work-.CorrCreate step 22, then email send out failure. 1st flow send email normally

// Create an embedded page of the correct class that will contain the address
myStepPage.getProperty(".pyAddresses").add(tools.findPage("CorrTemplate").getString("pyCorrType"), tools.findPage("CorrType").getString("pyAddressClass"));
try
{
    // Generate the HTML body of the correspondence and set it as pyBody
    StringMap params = new HashStringMap();
    params.putString("pxObjClass","Rule-Obj-Corr");
    params.putString("pyStreamName", tools.getParamValue("CorrName"));
    params.putString("pyCorrType", tools.findPage("CorrTemplate").getString("pyCorrType"));
    String getStreamResults = tools.getStream(params, tools.getPrimaryPage());
    myStepPage.getProperty(".pyBody").setValue(getStreamResults);
}
catch (Error e)
{
    errMessage = "Error obtaining html stream: " + e.getMessage();
}

error msg

Section 'EmailActions' execution error on page 'pyWorkPage' of  class 'CPA-GBS-CMS-Work-PPL-OutsideEmployment'. : null 

any idea this is?