Getting routes match error even if the routes are different

Question

I am getting an error like request has been matched with the multiple endpoints even if I have different routes defined for httpGet operations.

The code looks like as below,

[Route("api/[controller]")]
[ApiController]
public class CrmManagementController : ControllerBase
{
    [HttpGet("projects")]
    public async Task<ActionResult> ProjectInfo(
        [FromServices] ICrmProjects crmProjects,
        CancellationToken cancellationToken = default)
    {
        _ = crmProjects ?? throw new ArgumentNullException(nameof(crmProjects));

        var vantagepointProjects = await crmProjects.GetAllVantagepointProjectsByNumberAsync(cancellationToken).ConfigureAwait(false);

        return Ok(vantagepointProjects.Values);
    }

    [HttpGet("pursuits")]
    public async Task<ActionResult> PursuitInfo(
        [FromServices] ICrmProjects crmProjects,
        CancellationToken cancellationToken = default)
    {
        _ = crmProjects ?? throw new ArgumentNullException(nameof(crmProjects));

        var vantagepointPursuits = await crmProjects.GetAllVantagepointPursuitsByNumberAsync(cancellationToken).ConfigureAwait(false);

        return Ok(vantagepointPursuits.Values);
    }
}

Please let me know why I am getting the error and any suggestions to avoid the problem.

Update: Error details

fail: Microsoft.AspNetCore.Server.Kestrel[13]
      Connection id "0HN1DKQDVNS2Q", Request id "0HN1DKQDVNS2Q:00000001": An unhandled exception was thrown by the application.
      Microsoft.AspNetCore.Routing.Matching.AmbiguousMatchException: The request matched multiple endpoints. Matches:

      HTTP: GET /
      HTTP: GET / at Microsoft.AspNetCore.Routing.Matching.DefaultEndpointSelector.ReportAmbiguity(Span`1 candidateState)
         at Microsoft.AspNetCore.Routing.Matching.DefaultEndpointSelector.ProcessFinalCandidates(HttpContext httpContext, Span`1 candidateState)
         at Microsoft.AspNetCore.Routing.Matching.DefaultEndpointSelector.Select(HttpContext httpContext, Span`1 candidateState)
         at Microsoft.AspNetCore.Routing.Matching.DfaMatcher.MatchAsync(HttpContext httpContext)
         at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.Invoke(HttpContext httpContext)
         at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
         at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
         at Microsoft.WebTools.BrowserLink.Net.BrowserLinkMiddleware.InvokeAsync(HttpContext context)
         at Microsoft.AspNetCore.Watch.BrowserRefresh.BrowserRefreshMiddleware.InvokeAsync(HttpContext context)
         at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext](IHttpApplication`1 application)

Below is the configuration in program.cs file

app.UseEndpoints(endpoints =>
{
    endpoints.MapControllers();
    endpoints.MapControllerRoute(
        name: "default",
        pattern: "api/{controller}/{action}/{id?}");
    endpoints.MapGet("/", () => "This is the sample project");
});

Answer 1

The exception message mentions that there are conflicting endpoints/URLs for "/".

By removing this line:

endpoints.MapGet("/", () => "This is the sample project");

from the app.UseEndpoints() should resolve your issue.