Failed to create component

This is an issue caused by having multiple versions of Wisej installed side-by-side (in your case Wisej 3.5 and Wisej 4).

Visual Studio tries to load the design-time component assemblies, and if it picks up the wrong version (or a mix of 3.5 and 4), you’ll see “Failed to create component…” when dragging from the toolbox.

How to fix it:

1. Try cleaning and rebuilding your project, restarting Visual Studio, restarting your computer and cleaning and rebuilding your project again.
2. Clear the cache- Visual Studio caches assemblies for the toolbox and designer. Close Visual Studio, then delete the contents of these folders:
   C:\Users\<YourUsername>\AppData\Local\Microsoft\VisualStudio\<version>\ComponentModelCache
   C:\Users\<YourUsername>\AppData\Local\Microsoft\VisualStudio\<version>\Designer\ShadowCache
3. Check your project references- open your .vbproj file by double-clicking on the project name in the Solution Explorer. Double-check that it is referencing Wisej 4 (Should look like this: <PackageReference Include=”Wisej-4″ Version=”4.0.*-*” />) and not Wisej 3.5
4. Try temporarily uninstalling Wisej 3.5 (uninstall it from Visual Studio → Extensions → Manage Extensions)
5.  Reset the toolbox- Go to the Tools menu → Import and Export Settings. Select Reset all settings → click Next. You can choose Yes, save my current settings (optional) or No. Pick your default environment (e.g., VB or C#). This will rebuild the toolbox from scratch.

Hope this helps,

Julie