It sounds to me that plugins .meta data is corrupted.
Open Unity Editor and go to Assets/NoesisGUI/Plugins/Libraries.
Under each platform directory you will find the corresponding libraries, you should select them in inspector and make sure the following settings are set:
Windows/x86/Noesis.dll = Editor, x86, Windows | Standalone, Windows, x86
Windows/x86_64/Noesis.dll = Editor, x86_64, Windows | Standalone, Windows, x86_64
MacOS/Noesis.bundle = Editor, Any CPU, OSX | Standalone, Mac OS X, x86 + x86_64
Linux/x86/libNoesis.so = Editor, x86, Linux | Standalone, Linux, x86
Linux/x86_64/libNoesis.so = Editor, x86_64, Linux | Standalone, Linux, x86_64
Android/arm/libNoesis.so = Android, ARMv7
Android/x86/libNoesis.so = Android, x86
UWP/arm/Noesis.dll = WSAPlayer, UWP, ARM
UWP/x86/Noesis.dll = WSAPlayer, UWP, X86
UWP/x86_64/Noesis.dll = WSAPlayer, UWP, X64