What is wrong with ProjectNameDesigner.xaml file of UiPath Activity Creator?

I attempted to use this extension several times today for creating custom activity. However, every time I create a new project, input the required arguments in the newly created activity , and include some concatenation code in the activity file, the designer.xaml file consistently displays errors that are difficult to understand . Initially, I considered the possibility that the issue might be related to my custom icon for the activity. However, even after 7-8 attempts using the default icon, the error persists. Kindly refer to this previous question I have posted for more details on this matter.

EDIT:- Even this guys from UiPath i guess have faced the same error when opend the Designer.xaml file , But when they published the pakage it got published even though there was errors in designer.xaml file

Could you please show your error?
by photo
regards,

Please see this previous post