Hi, Support

When I use Fiddler Classic as a proxy in my program that uses SugarSync API, data reception fails due to sudden disconnection.

If I receive directly from the API server without going through Fiddler, there is no problem.
Whether it is a direct connection or Fiddler, the header and data of the server response are all the same.

When I look at Fiddler, all data is received, but when my program tries to get the data in the response, my Rebex Engine throws an error "Connection was closed by the remote connection end."

I also contacted Rebex, and they said that it is a close_notify error, so Fiddler does not handle it correctly.
In other words, I need to receive data after making a SugarSync API call, but the connection is disconnected without receiving a close_notify, so an error occurs when receiving data.

There is no problem in general when using Fiddler, but it only occurs when connecting to the SugarSync API server.

SugarSync API does not send Content-Length header and  Content-Type header in response.

In my opinion, since there is no Content-Length or Content-Type in the header, it seems that Fiddler suddenly disconnects the client.

I hope this report will help you improve your product.

Thank you,

Best regards

BooKyung Oh

Fiddler Capture (Some data and information has been truncated and marked as ...)

Request : 
POST https://api.sugarsync.com/authorization HTTP/1.1
Host: api.sugarsync.com
Content-Type: application/xml; charset=utf-8
Content-Length: 290
User-Agent: ...
Connection: keep-alive

<tokenAuthRequest>...</tokenAuthRequest>


Response : 
HTTP/1.1 201 Created
Content-Type: application/xml; charset=UTF-8
Date: Sat, 14 Jun 2025 02:48:36 GMT
Location: ...
Access-Control-Allow-Origin: *
Access-Control-Allow-Headers: X-Requested-With,Content-Type,Content-Length,Authorization,Range,X-SugarSync-API-Version
Access-Control-Expose-Headers: Location,Content-Disposition,Content-Length,Accept-Ranges,Date,Transfer-Encoding,Vary
Access-Control-Max-Age: 259200
Access-Control-Allow-Methods: GET,POST,DELETE,PUT
Server: Noelios-Restlet-Engine/1.1.5
Connection: close

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><authorization><expiration>2025-06-13T20:48:36.533-07:00</expiration><user>https://api.sugarsync.com/user/...</user></authorization>