Error - 12030 The connection with the server was terminated abnormally

[david_navigator 12]

Using Delphi to upload or download from a cloud S3 server, my customers are getting this intermittent error.

 

exception class    : ENetHTTPClientException
exception message  : Error sending data: (12030) The connection with the server was terminated abnormally.

thread $2f68:
01d4096a +126 HireTrackNX.exe System.Net.HttpClient.Win                           TWinHTTPClient.HandleExecuteError
01d40c76 +2d2 HireTrackNX.exe System.Net.HttpClient.Win                           TWinHTTPClient.DoExecuteRequest
01d4bda2 +1ea HireTrackNX.exe System.Net.HttpClient                               THTTPClient.ExecuteHTTPInternal
01d4c080 +008 HireTrackNX.exe System.Net.HttpClient                               THTTPClient.ExecuteHTTP
01d4b0f2 +0ee HireTrackNX.exe System.Net.HttpClient                               THTTPClient.Execute
01d4bb05 +04d HireTrackNX.exe System.Net.HttpClient                               THTTPClient.DoExecute
01d4fe18 +050 HireTrackNX.exe System.Net.HttpClient                               THTTPClient.Put
022b7f32 +03a HireTrackNX.exe Data.Cloud.CloudAPI                                 TCloudHTTP.Put
022b77e7 +077 HireTrackNX.exe Data.Cloud.CloudAPI                                 TCloudService.IssuePutRequest

 

Google seems to suggest it could be a Winsock timeout or a TLS mismatch between the target machine and console machine., but I have no understanding of what that actually means in practical terms - it certainly doesn't seem to be related to the size of the file being transferred.
Would that be something as simple as a network connection issue between the client & server ? The server's hosting company tell me there's no issue at their end and the user is connecting to the client over RDP, so there can't be an internet issue at their end either.

 

I'm really looking for any ideas or suggestions on how to either deal with the error better from a user's POV or how to diagnose what the actual cause is and address that.

 

Usually if the user retries the upload or download process a couple of times, it does eventually work.

 

Many thanks

 

David

 

Edited May 18, 2023 by david_navigator
added additional info

[Fr0sT.Brutal 897]

To investigate the issue, you should determine at which moment it happens. I'm not sure you can reach HTTPClient's internals but start with line number inside

TWinHTTPClient.DoExecuteRequest

in the call stack. Also check if it has any logging features. And try to gather as much info as possible - time, file size, concrete request, whether Internet is up at the moment of disconnect, etc