Intermittent C1 WebResource.axd failure on Azure App Service

Intermittent C1 WebResource.axd failure on Azure App Service

Posted by: thanhthuyeths on 30 January 2026, 3:13 am EST

• 

  thanhthuyeths

  • Post Options:
  • Link
    Copy

  Posted 30 January 2026, 3:13 am EST - Updated 30 January 2026, 3:22 am EST

  Dear Mescius Support Team,
  
  We are currently using ComponentOne ASP.NET Core MVC with the following environment:
  
  Product: ComponentOne for ASPNET Core (MVC)
  
  Version: 6,0,20233,352
  
  Hosting: Azure App Service (Windows)
  
  Runtime: ASPNET Core (NET 9)
  
  Issue Description:
  
  We are experiencing an intermittent production issue when using C1 controls (FlexGrid, etc.) that rely on C1 WebResources (/C1Resource.axd).

  Client-side error (Chrome):
  
  Uncaught SyntaxError: Unexpected end of input
  
  Server-side log:
  
  System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values. (Parameter ‘bytes’)
  
  at System.IO.Pipelines.Pipe.Advance(Int32 bytes)
  
  at Microsoft.AspNetCore.Server.IIS.Core.OutputProducer.WriteAsync(…)
  
  at C1.Web.Mvc.WebResourceInfo.WriteContent(Stream stream)
  
  at C1.Web.Mvc.WebResourcesResult.ExecuteResult(ActionContext context)

  Observations
  
  The error seems to happen when C1Resource.axd JS/CSS is partially written to the response stream
  
  This results in truncated JavaScript, causing Unexpected end of input

  The problem:
  
  -Does not occur locally
  
  -Is not reproducible consistently
  
  -Appears to be related to streaming responses under Azure IIS / HTTP2
  
  The layout uses:

  <c1-scripts>
      <c1-basic-scripts culture="ja" />
  </c1-scripts>

  Could you please help confirm:

  1. Whether this is a known issue/limitation of C1 WebResource streaming on Azure App Service
  2. If there is an official recommendation to use static Wijmo files for cloud hosting
  3. Whether a fix or improvement is planned for WebResource handling in future versions
  4. The recommended way to obtain static Wijmo JS/CSS that matches the installed C1 version

  Thank you very much for your support.
  
  We look forward to your guidance.

  Best regards,
  
  Thuyet Phan