Additional References Needed
If you are targeting .NET Framework 4, and use Visual Studio Toolbox to add EasyDAClient or EasyAEClient components to your Windows Forms application, you may get a build error in the designer-generated code for your form or control: “error CS0234: The type or namespace name 'Threading' does not exist in the namespace 'System.Windows' (are you missing an assembly reference?)”, near instantiation of DispatcherSynchronizationContext.
This error happens because the Visual Studio Designer “forgets” to reference one of the assemblies. In order to resolve this error, simply add a reference to WindowsBase assembly to your project.
Application Configuration File Changes
If you are targeting .NET Framework 4, you need to configure your application to properly load the core mixed-mode assembly of QuickOPC. In order to do so, add useLegacyV2RuntimeActivationPolicy="true" to ‘startup’ element in your application configuration file.
In Visual Studio, you typically design the contents of the application configuration file is in the app.config file in your project. After making this change, the file may look like this:
<?xmlversion="1.0"?>
<configuration>
<startupuseLegacyV2RuntimeActivationPolicy="true">
<supportedRuntimeversion="v4.0"/>
</startup>
</configuration>