I just make some trying, all the file i download and stucked is more then 8kb.The jpg file below 6kb i upload and it can be view in the virtual directory, but when i download and view it the result is "no preview available". And this is the result of the 6.XXkb .txt file i have download from my portal:
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<title>Cannot redirect after HTTP headers have been sent.</title>
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H1 { font-family:"Verdana";font-weight:normal;font-size:18pt;color:red }
H2 { font-family:"Verdana";font-weight:normal;font-size:14pt;color:maroon }
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<span><H1>Server Error in '/DotNetNuke' Application.<hr width=100% size=1 color=silver></H1>
<h2> <i>Cannot redirect after HTTP headers have been sent.</i> </h2></span>
<font face="Arial, Helvetica, Geneva, SunSans-Regular, sans-serif ">
<b> Description: </b>An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
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<b> Exception Details: </b>System.Web.HttpException: Cannot redirect after HTTP headers have been sent.<br><br>
<b>Source Error:</b> <br><br>
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<code>
The source code that generated this unhandled exception can only be shown when compiled in debug mode. To enable this, please follow one of the below steps, then request the URL:<br><br>1. Add a "Debug=true" directive at the top of the file that generated the error. Example:<br><br> <%@ Page Language="C#" Debug="true" %><br><br>or:<br><br>2) Add the following section to the configuration file of your application:<br><br><configuration><br> <system.web><br> <compilation debug="true"/><br> </system.web><br></configuration><br><br> Note that this second technique will cause all files within a given application to be compiled in debug mode. The first technique will cause only that particular file to be compiled in debug mode.<br><br>Important: Running applications in debug mode does incur a memory/performance overhead. You should make sure that an application has debugging disabled before deploying into production scenario.</code>
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<b>Stack Trace:</b> <br><br>
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<code><pre>
[HttpException (0x80004005): Cannot redirect after HTTP headers have been sent.]
System.Web.HttpResponse.Redirect(String url, Boolean endResponse) +3208573
DotNetNuke.Services.Exceptions.Exceptions.ProcessPageLoadException(Exception exc, String URL) +302
DotNetNuke.Framework.PageBase.Page_Error(Object Source, EventArgs e) +375
System.Web.UI.TemplateControl.OnError(EventArgs e) +105
System.Web.UI.Page.HandleError(Exception e) +73
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +6944
System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +154
System.Web.UI.Page.ProcessRequest() +86
System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) +18
System.Web.UI.Page.ProcessRequest(HttpContext context) +49
ASP.default_aspx.ProcessRequest(HttpContext context) +4
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +154
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +64
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<b>Version Information:</b> Microsoft .NET Framework Version:2.0.50727.42; ASP.NET Version:2.0.50727.210
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<!--
[HttpException]: Cannot redirect after HTTP headers have been sent.
at System.Web.HttpResponse.Redirect(String url, Boolean endResponse)
at DotNetNuke.Services.Exceptions.Exceptions.ProcessPageLoadException(Exception exc, String URL)
at DotNetNuke.Framework.PageBase.Page_Error(Object Source, EventArgs e)
at System.Web.UI.TemplateControl.OnError(EventArgs e)
at System.Web.UI.Page.HandleError(Exception e)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context)
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at ASP.default_aspx.ProcessRequest(HttpContext context)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.