Not able to upload .iso file to asset directory on Proget

[Sigve.opedal_6476]

Hi all.

I'm trying to make a ISO file available through a asset directory, but when trying to upload (using browser), it always fails after 3% upload. The file is 1.3 GB in size. Uploading other files (300 MB .exe file) seems to work OK.

I was able to work around this by compressing the .iso tile to a .zip file and then using the "Import from zip file" function. But uploading the .iso file directly does not work for me.

We are on version 2025.18 running in docker on Linux. Here is the error from the log

Failed to upload Standard_Edtn_2025_64Bit.ISO: Connection reset by peer

Microsoft.AspNetCore.Connections.ConnectionResetException: Connection reset by peer
 ---> System.Net.Sockets.SocketException (104): Connection reset by peer
   --- End of inner exception stack trace ---
   at System.IO.Pipelines.Pipe.GetReadResult(ReadResult& result)
   at System.IO.Pipelines.Pipe.ReadAsync(CancellationToken token)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.Http1ContentLengthMessageBody.ReadAsyncInternal(CancellationToken cancellationToken)
   at System.Runtime.CompilerServices.PoolingAsyncValueTaskMethodBuilder`1.StateMachineBox`1.System.Threading.Tasks.Sources.IValueTaskSource<TResult>.GetResult(Int16 token)
   at System.IO.Pipelines.PipeReader.CopyToAsyncCore[TStream](TStream destination, Func`4 writeAsync, CancellationToken cancellationToken)
   at Inedo.ProGet.WebApplication.FeedEndpoints.Assets.AssetContentHandler.UploadPartAsync(AhHttpContext context, WebApiContext apiContext, AssetFeed feed, String url) in C:\Users\builds\AppData\Local\Temp\InedoAgent\BuildMaster\192.168.44.60\Temp\_E627829\Src\src\ProGet\WebApplication\FeedEndpoints\Assets\AssetContentHandler.cs:line 276
   at Inedo.ProGet.WebApplication.FeedEndpoints.Assets.AssetContentHandler.UploadPartAsync(AhHttpContext context, WebApiContext apiContext, AssetFeed feed, String url) in C:\Users\builds\AppData\Local\Temp\InedoAgent\BuildMaster\192.168.44.60\Temp\_E627829\Src\src\ProGet\WebApplication\FeedEndpoints\Assets\AssetContentHandler.cs:line 291
   at Inedo.ProGet.WebApplication.FeedEndpoints.Assets.AssetContentHandler.UploadFileAsync(AhHttpContext context, WebApiContext apiContext, AssetFeed feed, String url, PutMode mode, Boolean ignoreContentType) in C:\Users\builds\AppData\Local\Temp\InedoAgent\BuildMaster\192.168.44.60\Temp\_E627829\Src\src\ProGet\WebApplication\FeedEndpoints\Assets\AssetContentHandler.cs:line 168
   at Inedo.ProGet.WebApplication.FeedEndpoints.Assets.AssetFineUploadHandler.TryProcessRequestAsync(AhHttpContext context, WebApiContext apiContext, AssetFeed feed, String relativeUrl) in C:\Users\builds\AppData\Local\Temp\InedoAgent\BuildMaster\192.168.44.60\Temp\_E627829\Src\src\ProGet\WebApplication\FeedEndpoints\Assets\AssetFineUploaderHandler.cs:line 29

::Asset Upload Error on 01/14/2026 11:24:44::

[Dan_Woolf]

Hi @Sigve-opedal_6476,

A 104 Socket Exception typically means that a firewall is blocking the upload of the file. Do you have a firewall sitting between your browser and your ProGet server?

Thanks,
Dan

[Sigve.opedal_6476]

@Dan_Woolf yes, there is a firewall, but I’m able to upload other files from the same workstation, just not isos. My workaround was to zip the iso and then upload.

[Dan_Woolf]

Hi @Sigve-opedal_6476,

I just tested with a 3GB .iso file and could upload without issue. When you tested locally on the same workstation, did you use http://localhost or the normal URL? Chances are the normal URL will still go through the firewall, even when on the same workstation. I would check in with your IT team and see if they are blocking .iso upload files to your ProGet instance.

Thanks,
Dan