Not compatible with new .Net 6 project?

[DreamU1952]

NuGet says this package is compatible with .Net 6 but I cannot get it to compile (VS2022). If a take a successful .Net 5 project and simply change the Target Framework to .Net 6 I can get a successful compile and execution of this extended toolkit (v5.0.100). But if I create a new .Net 6 wpf project and add the package I get a 'namespace prefix extToolKit is not defined' error. Using the same namespace as .Net 5 which is "http://schemas.xceed.com/wpf/xaml/toolkit."

[georg-eckert-zeiss]

We too use it successfully in a .NET 6 project.