Troubleshooting

Common issues and solutions:

WCF and client/server communication

  • For REST calls, use HttpClient instead of WebClient.

  • The browser security context may require that you enable cross-domain calls by configuring CORS and the SameSite attribute.

  • When adding a WCF Service Reference, please uncheck the option "Reuse types in referenced assemblies", and update the NuGet packages from v4.4 to v4.7. When configuring a WCF Service Reference, temporarily add a reference to the "System.dll" assembly, then configure the service, and remove the reference after you are done.

  • To enable passing cookies (eg. for credentials/authentication), set the "DefaultSoapCredentialsMode" parameter.

  • For applications using RIA Services (like the "Business Application" template), be sure to refer to the tutorial and the "Troubleshooting" section of the Business Applications documentation.

Debugging

  • If your breakpoints are not hit, try disabling "Enable just my code" (uncheck the option in Tools->Options->Debugging->General->Enable Just My Code)

  • Disabling code optimisation may help if you experience debugging issues (right click the project->Properties->Build->uncheck "optimize code")

XAML files

  • All XAML files in the project need to have the following properties: Build Action = Content, CustomTool = MSBuild:Compile

  • If you only change XAML files without changing C# (or VB.NET or F#) files, you may need to manually Rebuild the solution to see the changes reflected in your app.

Other

Common issues with code trimming and WCF/SOAP data contract serialization

Code trimming is an optimization that can reduce the size of a published OpenSilver application, thus improving both performance and start-up time. For more information you can read the official documentation here.

However, in some scenarios, is it possible that code trimming breaks .NET serialization and/or deserialization that rely heavily on Reflection.

If you receive an error on data contract serialization or deserialization (or if you use Reflection in your application) you can disable code trimming.

To do so, just edit the “.Browser” project file and make sure that the PublishTrimmed flag is set to False. Below you will find an example.

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If disabling trimming helps to solve the issue, please, consider reverting trimming and configure trimming rules. To do this, please, follow the instructions here.

FAQ - Other issues and solutions

> I am getting "Error MSB4018: The "ResolveBlazorRuntimeDependencies" task failed unexpectedly." when I compile.

Make sure that all the projects in your solution use the exact same OpenSilver NuGet package name and version.

For example, this error may occur if one project references the "OpenSilver" package while another project references the "OpenSilver.WorkInProgress" package.

> How to see more detailed logs?

Build output verbosity can be changed from Tools -> Options -> Projects and Solutions -> Build and Run
Choose an option from MSBuild project build output verbosity

> What if my issue is not listed here?

Please contact us at: https://opensilver.net/contact.aspx