How to add a value which is in JSON format in multipart/formdata in soapUI

Form-data(example) start:

Name1 : Aravind

age : 24

Details:{"Height":"170cms", "weight":"70kgs", "Education":{"Primary":"xyz", "Degree":"abc","PG":"ABCXYZ123456","URL":"aboutMe.com"}}

Form-data(example) End

For the above form data i have give post body like below in the SoapUI

Header:  Content-Type: multipart/form-data; boundary="123121"

Post Body given in SoapUI:

--123121

Content-Disposition: form-data; name="Name1"

Aravind

--123121

Content-Disposition: form-data; name="age"

24

--123121

Content-Disposition: form-data; name="Details"

{"Height":"170cms", "weight":"70kgs", "Education":{"Primary":"xyz", "Degree":"abc","PG":"ABCXYZ123456","URL":"aboutMe.com"}}

--123121--

i am getting CDATA[Line length limit 100 exceeded.] ERROR. Could anyone please help me with this?