validation error while creating api ticket

Dear team 

Getting below validation error while creating ticket from api v2 

I have added all mandatory fields but still same 

Can anyone please check and advice 

{

    "description": "Validation failed",

    "errors": [

        {

            "field": "lsungsversion",

            "message": "It should be of type String",

            "code": "missing_field"

        }

    ]

}