guitar fingering 'a' \RH doesn't seem to work

[Jay Hamilton]

I have tried to use 
note-digit
e'16-a
that won't work log gives me "unexpected notename pitch."
Tried from the manual 
e'16-\rightHandFinger #4
and that did nothing no 'a'
version
2.10.25


Yours-
Jay

Jay Hamilton
www.soundand.com
206-328-7694