Cannot download files in .Net 6 - model-view-controller

Question

I have an MVC .Net Core 2.1 application. It has an action that generates a .csv file and returns it to download. Now, as this .Net version is not supported, I created a new application with .NET 6, and moved there my controllers, views etc. from the old application. Now for some reason download does not work. The execution does not even reach the action, and I get this error:
No webpage was found for the web address:
https://localhost:44398/Reports/InventoryReportAsync HTTP ERROR 404
So it is looking for the view by the action name, but this view obviously does not exist.
Here is my code:
_Layout.cshtml
<div class="dropdown">
<button type="button" class="btn btn-primary dropdown-toggle" data-bs-toggle="dropdown" aria-expanded="false">Reports</button>
<ul class="dropdown-menu">
<li><a class="dropdown-item" asp-controller="Reports" asp-action="InventoryReportAsync">Inventory Report</a></li>
<li><a class="dropdown-item" asp-controller="Reports" asp-action="ItemReorderReportAsync">Item Reorder Report</a></li>
<li><a class="dropdown-item" asp-controller="Reports" asp-action="OrderHistoryReport">Order History Report</a></li>
</ul>
</div>
ReportsController.cs
public async Task<IActionResult> InventoryReportAsync()
{
try
{
List<InventoryReportDto> reportModel = await _itemRepository.GetInventoryReportDtosAsync();
return await Export<InventoryReportDto, InventoryReportCsvMap>(reportModel, "InventoryReport.csv");
}
catch (Exception ex)
{
return StatusCode(500, new { ex.Message });
}
}
protected async Task<IActionResult> Export<T, M>(List<T> exportModel, string fileName) where T : class where M : ClassMap
{
MemoryStream stream = new MemoryStream();
StreamWriter streamWriter = new StreamWriter(stream)
{
AutoFlush = true
};
CsvWriter csv = new CsvWriter(streamWriter, CultureInfo.InvariantCulture);
csv.Context.RegisterClassMap<M>();
csv.WriteRecords(exportModel);
await csv.FlushAsync();
stream.Position = 0;
return File(stream, "application/octet-stream", fileName);
}
ADDED:
Program.cs
app.MapControllerRoute(
name: "default",
pattern: "{controller=Home}/{action=Index}/{id?}");
app.MapRazorPages();
This is how it looked in .Net 2.1:
Startup.cs
app.UseMvc(routes =>
{
routes.MapRoute(
name: "default",
template: "{controller=Home}/{action=Index}/{id?}");
});

Answer 1

I posted this question elsewhere, and got an answer here:
https://learn.microsoft.com/en-us/answers/questions/874470/cannot-download-files-in-net-6.html
I just needed to remove the "Async" suffix from the action name here:
<div class="dropdown">
<button type="button" class="btn btn-primary dropdown-toggle" data-bs-toggle="dropdown" aria-expanded="false">Reports</button>
<ul class="dropdown-menu">
<li><a class="dropdown-item" asp-controller="Reports" asp-action="InventoryReport">Inventory Report</a></li>
<li><a class="dropdown-item" asp-controller="Reports" asp-action="ItemReorderReport">Item Reorder Report</a></li>
<li><a class="dropdown-item" asp-controller="Reports" asp-action="OrderHistoryReport">Order History Report</a></li>
</ul>
</div>