Thanks for the update! Just tried, getting this error for many of my XAMLs. Works Ok in 5.6. I deleted teh NoesisGUI folder, got the 2.1 beta one, reimport all.
This is the error:
NoesisException: Assets/XAMLs/Themes/FanStyle.xaml(1): Invalid token.
Noesis.Error.Check () (at Assets/NoesisGUI/Plugins/API/Core/NoesisError.cs:21)
Noesis.GUI.Noesis_LoadXaml_ (System.String xaml) (at Assets/NoesisGUI/Plugins/API/Core/NoesisGUI.cs:263)
Noesis.GUI.LoadXaml (System.String xaml) (at Assets/NoesisGUI/Plugins/API/Core/NoesisGUI.cs:120)
NoesisXaml.Load () (at Assets/NoesisGUI/Plugins/NoesisXaml.cs:35)
NoesisXamlEditor.CreatePreviewGUIView () (at Assets/NoesisGUI/Plugins/Editor/NoesisXamlEditor.cs:48)
UnityEngine.Debug:LogException(Exception)
NoesisXamlEditor:CreatePreviewGUIView() (at Assets/NoesisGUI/Plugins/Editor/NoesisXamlEditor.cs:60)
NoesisXamlEditor:RenderStaticPreview(String, Object[], Int32, Int32) (at Assets/NoesisGUI/Plugins/Editor/NoesisXamlEditor.cs:225)
UnityEditor.AssetPreviewUpdater:CreatePreviewForAsset(Object, Object[], String)
Opened bug
https://bugs.noesisengine.com/view.php?id=1146