Troubleshootinglink

Build errorlink

Radzen Blazor Studio builds your application in order to show it in design time. Sometimes this build fails and you will see the "Oh, no! The build failed." message which also asks you to check the Output window. The build could fail for two reasons:

1. Your application doesn't build in general in its current state. If your application fails to build in Visual Studio or from command line then it won't build in Radzen Blazor Studio as well. Fix the reported errors and try again.
2. Your application builds and runs as expected but Radzen Blazor Studio fails with the design-time build. This usually happens when Radzen Blazor Studio didn't recognize some vital part of your application startup and didn't include it in the design-time build - some service registration for example. In other cases it is some startup code that throws an exception during design-time build. You can use Radzen Blazor Studio to analyze your project for problems and send us the output.

Hide code from design-time buildslink

Use the RADZEN preprocessor constant if there is code you don't want Radzen Blazor Studio to include in design-time builds.

In C# files

#if !RADZEN
// This code will not be included in Radzen Blazor Studio design-time builds
builder.Services.AddScoped<ITradeService, TradeService>();
#endif

In razor files

@{ #if !RADZEN }
<RadzenButton Text="Hidden in design builds" />
@{ #endif }

Preview and release candidate versions of .NETlink

Sometimes the design time build would fail with errors such as CS0246: The type or namespace name 'App' could not be found. This isually means that you have installed a preview or release candidate version of the .NET framework which Radzen Blazor Studio does not support. Visual Stidio 2022 Preview installs such .NET framework versions.

You can find the latest installed version by running dotnet --info in command prompt.

To solve this problem you have two options:

• Uninstall the preview version and install the latest official version of .NET 9. If it has been installed by Visual Studio 2022 Preview you would need to uninstall the VS 2022 Preview itself and get the RTM version.
• Create a global.json file in the directory of your application with the following contents:

{
  "sdk": {
    "version": "9.0.200"
  }
}

Render errorlink

Sometimes certain pages may fail to display in Radzen Blazor Studio. You will see the "Oh, no! Page threw exception during rendering." message.

Radzen Blazor Studio does not execute the Blazor lifecycle methods of your pages in order to prevent unwanted side effects such as database access, HTTP requests or file system access. Instead it adds code that initializes the page members (properties and fields) with sample data. This process could fail in some cases. You can use Radzen Blazor Studio to analyze your project for problems and send us the output.

Package restore errorslink

If you get error NU1301: Failed to retrieve information about XXX from remote source make sure the default NuGet package source is nuget.org. Any third party package sources should come after it. You can verify that from Visual Studio.

Analyzelink

Radzen Blazor Studio can analyze your project for potential design-time build or render issues. If you experience problems here is how to run the analysis.

Note: The analyze option requires Radzen Blazor Studio 1.0.6+.

You can terminate the analysis at any time by pressing CTRL+C (Windows) or CMD+C (macOS).

Analyze on Windowslink

Open a command prompt. Then run the following command

dotnet "c:\Program Files\Radzen Blazor Studio\resources\Radzen.Server\Radzen.Server.dll" --analyze <path to the .sln or .csproj of your application> -o <log file>

For example

dotnet "c:\Program Files\Radzen Blazor Studio\resources\Radzen.Server\Radzen.Server.dll" --analyze c:\apps\BlazorApp\BlazorApp.sln -o log.txt

This command will analyze the c:\apps\BlazorApp\BlazorApp.sln solution and output the information to the log.txt file. You can omit the -o log.txt parameter if you want to see the output in the console.

Analyze on macOSlink

Open a terminal. Then run the following command

dotnet /Applications/Radzen\ Blazor\ Studio.app/Contents/Resources/Radzen.Server/Radzen.Server.dll --analyze <path to the .sln or .csproj of your application> -o <log file>

For example

dotnet /Applications/Radzen\ Blazor\ Studio.app/Contents/Resources/Radzen.Server/Radzen.Server.dll --analyze ~/apps/BlazorApp/BlazorApp.sln -o log.txt

This command will analyze the ~/apps/BlazorApp/BlazorApp.sln solution and output the information to the log.txt file. You can omit the -o log.txt parameter if you want to see the output in the console.

Report an issuelink

If you hit a problem with Radzen Blazor Studio you can report it by:

• Starting a forum thread
• Sending us an email to info@radzen.com (only for Radzen Blazor Studio Professional or Enterprise subscribers)

If you have a log file from analyzing your project attach it to your report.

Log filelink

Radzen Blazor Studio logs various info (including unexpected exceptions and other problems). The location depends on the host OS:

Windowslink

%APPDATA%\Radzen Blazor Studio\log.txt

macOSlink

~/Library/Application Support/Radzen Blazor Studio/log.txt

Linuxlink

~/.config/Radzen Blazor Studio/log.txt or $XDG_CONFIG_HOME/Radzen Blazor Studio/log.txt

CSS does not load in design timelink

Radzen Blazor Studio will search for _Host.cshtml or index.html files in your application and parse them for CSS and JS. It also supports component specific CSS files (*.razor.css).

If you are including a CSS file by other means they may not display in design-time.

Code in lifecycle methods does not execute in design-timelink

Radzen Blazor Studio does not execute the Blazor lifecycle methods of your pages in order to prevent unwanted side effects such as database access, HTTP requests or file system access. Instead it adds code that initializes the page members (properties and fields) with sample data.

You can enable the Blazor lifecycle from Radzen Blazor Studio settings (the button in the bottom left corner). Do so at your own risk.

Changes do not appear when the application is runlink

Radzen Blazor Studio does not automatically save file changes. Press ctrl+S to save the current file or ctrl+alt+S to save all open files.