[REST] How do I resolve error: "Content type 'text/plain;charset=UTF-8' not supported" in Postman

[HungDo]

Problem: 

When using postman, a common error that appears in the response is "Content type 'text/plain;charset=UTF-8"

For example:

{ 
"success": false, 
"processId": "F78F89686A347317", 
"reasons": [ 
{ 
"code": 50000000, 
"message": "Content type 'text/plain;charset=UTF-8' not supported" 
} 
] 
}

In order to fix this, please locate to your postman under "Headers" and include the key "Content-Type" and value "application/json"