While concatenating two large text field using scripted field, if string length are long not able to concatenate

Elastic Stack Kibana
1

Not able to concatenating two string fields in kibana using the painless script, having a very large string. My scripts are as follow :-:
'''
if (doc['ERROR'].size() != 0 && doc['ABORT'].size() != 0 && doc['FAIL'].size()!=0 && doc['STATUS 502'].size()!=0) {
'<<<Error'+doc['ERROR'].value+'>>><<Fail:'+doc['FAIL'].value+'>><<Abort:'+doc['ABORT'].value+'>><<<STATUS 502:'+doc['STATUS 502'].value+'>>>'
}else{
"No Desciption"
}
'''
here Error field data is too long so in scripted field result not able to concatenate. and when i further investigate it doc['field'].size() return null value.

2

What's the error you're getting?

3

getting no error data is not loading in place of data it is showing else condition, Infact data is present there.
Thanks