Integration with Behavior

Radio Button++ CustomField ist not recognized by Behavior (script runner). I used the same code with normal radio button and it worked fine, but with ++ nothing happens.
Code (to hide verifier field if value of verification needed is yes:
def verificationNeededCF = getFieldById("customfield_11506") //Radio Button++ ID: customfield_11121
String verificationNeeded = verificationNeededCF.getValue()
def verifierField = getFieldById("customfield_11120")
log.info("verification needed: "+verificationNeeded)
def desc = getFieldById("description")
desc.setFormValue("xxx: "+verificationNeeded)
if (verificationNeeded.contains("Yes")){
verifierField.setHidden(false)
verifierField.setRequired(true)
} else
{
verifierField.setHidden(true)
verifierField.setRequired(false)
}