function isWasmSupported() {
    try {
        if (typeof WebAssembly === "object"
            && typeof WebAssembly.instantiate === "function") {
            const module = new WebAssembly.Module(Uint8Array.of(0x0, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00));
            if (module instanceof WebAssembly.Module)
                return new WebAssembly.Instance(module) instanceof WebAssembly.Instance;
        }
    } catch (e) {
    }
    return false;
}
  
if(!isWasmSupported()) { 
  alert("WebAssembly is not available in your browser. Please try using the latest version of Chrome, Firefox, Edge or Safari.");
}

[_Host.cshtml]

<script src="_framework/blazor.server.js"></script>
<script>
window.Blazor.defaultReconnectionHandler.onConnectionDown = function () {
     setTimeout(function () {
             location.reload();
     }, 7000);
}

window.Blazor.defaultReconnectionHandler._reconnectCallback = function (d) {
    document.location.reload();
}
</script>

<PropertyGroup>
    <BlazorLinkOnBuild  Condition="'$(Configuration)'!='Release'">false</BlazorLinkOnBuild>
</PropertyGroup>

crit: Microsoft.AspNetCore.Components.WebAssembly.Rendering.WebAssemblyRenderer[100]
      Unhandled exception rendering component: Arg_NoDefCTor, Wasm.Shared.MainLayout
System.MissingMethodException: Arg_NoDefCTor, Wasm.Shared.MainLayout
   at System.RuntimeType.CreateInstanceMono(Boolean , Boolean )
   at System.RuntimeType.CreateInstanceDefaultCtor(Boolean , Boolean )
   at System.Activator.CreateInstance(Type , Boolean , Boolean )
   at System.Activator.CreateInstance(Type , Boolean )
   at System.Activator.CreateInstance(Type )
   at Microsoft.AspNetCore.Components.DefaultComponentActivator.CreateInstance(Type )
   at Microsoft.AspNetCore.Components.ComponentFactory.InstantiateComponent(IServiceProvider , Type )
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.InstantiateComponent(Type )
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.InstantiateChildComponentOnFrame(RenderTreeFrame& , Int32 )
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.InitializeNewComponentFrame(DiffContext& , Int32 )
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.InitializeNewSubtree(DiffContext& , Int32 )
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.InsertNewFrame(DiffContext& , Int32 )
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForRange(DiffContext& , Int32 , Int32 , Int32 , Int32 )
   at Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.ComputeDiff(Renderer , RenderBatchBuilder , Int32 , ArrayRange`1 , ArrayRange`1 )
   at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder , RenderFragment , Exception& )
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.RenderInExistingBatch(RenderQueueEntry )
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessRenderQueue() blazor.webassembly.js:1:38555

<Router AppAssembly="@typeof(App).Assembly">
    <Found Context="routeData">
        <RouteView RouteData="@routeData" DefaultLayout="@typeof(MainLayout)" />
        <FocusOnNavigate RouteData="@routeData" Selector="h1" />
    </Found>
    <NotFound>
        <PageTitle>Not found</PageTitle>
        <LayoutView Layout="@typeof(MainLayout)">
            <p role="alert">Sorry, there's nothing at this address.</p>
        </LayoutView>
    </NotFound>
</Router>

 <CascadingAuthenticationState>
      <Router AppAssembly="typeof(App).Assembly"  PreferExactMatches="true">
          <Found Context="routeData">
          <AuthorizeRouteView RouteData="@routeData" DefaultLayout="@typeof(MainLayout)">
                    <Authorizing>
                        <FocusOnNavigate RouteData="@routeData" Selector="h1"/>
                    </Authorizing>
                    <NotAuthorized>

                      @*  <RedirectToLogin/>*@


                    </NotAuthorized>
                </AuthorizeRouteView>
            </Found>
            <NotFound>
                <LayoutView Layout="@typeof(MainLayout)">
                      <span>Error</span>
                 </LayoutView>
            </NotFound>
        </Router>
    </CascadingAuthenticationState>