HTTP Error 400. The request has an invalid header name - Post request to D 365 F&O oData service from Fiddler

An error "HTTP Error 400. The request has an invalid header name" comes when we do Post request to D 365 F&O oData service as below from Fiddler.

Request message:
POST https:axurl/data/XXX HTTP/1.1
Content-Type: application/json; charset=utf-8
Authorization: Bearer
Host: axurl
{
"@odata.type":"#Microsoft.Dynamics.DataEntities.XXX",
"dataAreaId":"YYY"
}

Error message:
HTTP/1.1 400 Bad Request
Content-Type: text/html; charset=us-ascii
Server: Microsoft-HTTPAPI/2.0
Date: Fri, 11 Jan 2019 14:54:42 GMT
Connection: close
Content-Length: 339

Bad Request - Invalid Header

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HTTP Error 400. The request has an invalid header name.

The solution to resolve this error is just add extra space between header and body as below

POST https:axurl/data/XXX HTTP/1.1
Content-Type: application/json; charset=utf-8
Authorization: Bearer
Host: axurl

{
"@odata.type":"#Microsoft.Dynamics.DataEntities.XXX",
"dataAreaId":"YYY"
}