ERROR: KeyError: key :flatten not found

[rayacode]

I get this error
ERROR: KeyError: key :flatten not found
Stacktrace:
[1] __getproperty
@ ....julia\packages\PyCall\twYvK\src\PyCall.jl:313 [inlined]
[2] getproperty
@ ....julia\packages\PyCall\twYvK\src\PyCall.jl:318 [inlined]
[3] annotation(part::PyCall.PyObject, fgs::Vector{DataStructures.SortedDict{MIDI.Note, PianoFingering.Finger}})
@ PianoFingering .....PianoFingering.jl\src\process.jl:78
[4] fingering(file_name::String)
@ PianoFingering .....PianoFingering.jl\src\process.jl:23
[5] top-level scope
@ REPL[4]:1