I have a formlayout error when running a Blazor website

Question

I updated visual studio 19 and before that my site ran exactly how i intended it. Now i am getting an error when i load the home page but then breaks before it can finish loading it. I have provided the error code below. I also would let you know that i have seen this post ( How to turn on CircuitOptions.DetailedErrors? ) and tried it all but it hasn't worked.

Information: Normalizing '_blazor' to 
'http://fakesite.com/_blazor'.

Error: There was an unhandled exception on the current circuit, so this 
circuit will be terminated. For more details turn on detailed exceptions in 
'CircuitOptions.DetailedErrors'

Information: Connection disconnected.

new error after implementing Hanks solution

Error: Microsoft.JSInterop.JSException: Could not find 'FormLayout' in 'window.DxBlazor'.
Error: Could not find 'FormLayout' in 'window.DxBlazor'.
    at http://fakesite.com/_framework/blazor.server.js:8:27768
    at Array.forEach (<anonymous>)
    at d (http://fakesite.com/_framework/blazor.server.js:8:27729)
    at http://fakesite.com/_framework/blazor.server.js:8:28342
    at new Promise (<anonymous>)
    at e.beginInvokeJSFromDotNet (http://fakesite.com/_framework/blazor.server.js:8:28316)
    at http://fakesite.com/_framework/blazor.server.js:1:19148
    at Array.forEach (<anonymous>)
    at e.invokeClientMethod (http://fakesite.com/_framework/blazor.server.js:1:19119)
    at e.processIncomingData (http://fakesite.com/_framework/blazor.server.js:1:17165)
   at Microsoft.JSInterop.JSRuntimeBase.InvokeWithDefaultCancellation[T](String identifier, IEnumerable`1 args)
   at Microsoft.AspNetCore.Components.Rendering.Renderer.GetErrorHandledTask(Task taskToHandle)

this is the CreateWebHostBuilder method

public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
     WebHost.CreateDefaultBuilder(args)
     .UseSetting(WebHostDefaults.DetailedErrorsKey, "true")
     .CaptureStartupErrors(true)
     .UseStartup<Startup>();

Vehement

Can you post your CreateWebHostBuilder method code? – Automation

Hey @Automation , i have added the method to my post – Vehement

Are you using the latest version .NET Core 3.0 Preview 8? The latest Visual Studio 2019 update was afaik for the Preview 8. Could be a .NET Core versioning problem. – Cede

Hey @PascalR. , i am using the latest version .NET Core 3.0 Preview 8. – Vehement

What you have posted is OK, but what about the hosting? Are WebSockets enabled? How do you deploy (Self-contained or not?) – Jay

Ok, it now looks like a problem with hosting or publishing. Do you have (and use) an option like "Remove additional files at destination" ? – Jay

@HenkHolterman No i do not have an option like that – Vehement

Well, inform us about how you deploy to what host. – Jay

You seem to use DevExpress for Blazor. Have you updated the DevExpress NuGet package to the latest version preview 8? Are there four files in wwwroot/lib/dx-blazor? – Cede

Hey @HenkHolterman i publish it to IIS on a local Microsoft sever – Vehement

Hey @PascalR. yes i am using DevExpress and i have the latest preview 8 v0.2.0. i also have all the necessary files as to what there github describes. – Vehement

Another user seems to have had the same problem in this stackoverflow question: #57609702 He solved it by deleting his browser cache / cookies. Does that work for you? – Cede

@PascalR. i do not believe his problem is the same as mine, but i tried it anyway and to no avail. – Vehement

Answer 1

After the update to visual studios there was updares to all my NuGet packages too. This included the DevExpress for Blazor NuGet package and with that update they changed the link to the dx-blazor.js and dx-blazor.css files that your supposed to put I your layout’s HEAD section.

From:

<link href="lib/dx-blazor.css" rel="stylesheet" />
<script src="lib/dx-blazor.js"></script>

To:

<link href="lib/dx-blazor/dx-blazor.css" rel="stylesheet" />
<script src="lib/dx-blazor/dx-blazor.js"></script>

Hope this maybe helps others in my situation or in a situation similar to mine.

Vehement

Answer 2

Start by taking the advice literally.

In Startup.ConfigureServices:

services
  .AddServerSideBlazor()
  .AddCircuitOptions(options => { options.DetailedErrors = true; });

and then post the results here.

Jay

Answer 3

It seems that this is issue is related to client scripts. If you see "window.DxBlazor" in the message, this means that you need to look for the cause in the client scripts. Please make sure that you have the latest up-to-date DevExpress scripts included in your project. See the 6th item of the How to create a new project paragraph.    

Hexaemeron