Do you have your Studio project opened from a zip/rar file? If yes, make sure that the first is extracted.
Also, check if the xaml file is set to be read-only. If yes, diable this checkbox.
Do you have your Studio project opened from a zip/rar file? If yes, make sure that the first is extracted.
Also, check if the xaml file is set to be read-only. If yes, diable this checkbox.