I had to reinstall uipath from scratch. (just clean all registry entries)
Now i get this error:
The project ‘C:\Users\AntonioFernandes\Desktop\UiPath$Fundos.Get Excel and access site\project.json’ could not be opened: The package is missing the required nuspec file. Path: C:\Users\AntonioFernandes.nuget\packages\system.buffers\4.5.1.
Open the Main.xaml file in that project folder and then it will create project.json file automatically. And then publish the project by clicking Publish button in studio and check it.
I couldn’t open an xaml or a json file and I also could not create a new one.
It solved now with suggestion from Sudharsan.
I delete folder C:\Users\AntonioFernandes.nuget\packages\system.buffers
(i really rename it to system.buffers.bak)
and when I open the xaml file or json project it creates again the system.buffers folder