Can’t delete sticky notes.
The “Sticky notes” on Windows 10.1607 has been a Windows Store app while in previous versions it was a desktop app.The snt file is located under %AppData%\Roaming\Microsoft\Sticky Notes.You may try deleting them from there.
You can also import sticky notes.exe from C:\Windows\System32 of earlier versions.
If you cannot find the exe file, you may need to repair or restore it by running following commands:
Dism /Online /Cleanup-Image /RestoreHealth