Troubleshooting

Build error

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 builds

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 }

Render error

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.

Analyze

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 Windows

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 macOS

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 issue

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

  • Starting a forum thread
  • Opening a Github issue
  • 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 file

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

Windows

%APPDATA%\Radzen Blazor Studio\log.txt

macOS

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

Linux

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

CSS does not load in design time

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-time

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 run

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.