undefined method `enabled?' for nil:NilClass (NoMethodError)

[Deftaudio]

Hi, I'm trying to get running open-midinous on macOS Ventura and it fails on loading unimidi 0.5.1 library:

% ruby midinous.rb
/Library/Ruby/Gems/2.6.0/gems/unimidi-0.5.1/lib/unimidi/device.rb:101:in `use_device': undefined method `enabled?' for nil:NilClass (NoMethodError)
	from /Library/Ruby/Gems/2.6.0/gems/unimidi-0.5.1/lib/unimidi/device.rb:77:in `use'
	from /Users/andrei/Downloads/open-midinous-master/lib/midinous/proc_midi.rb:29:in `initialize'
	from /Users/andrei/Downloads/open-midinous-master/lib/midinous/proc_midi.rb:120:in `new'
	from /Users/andrei/Downloads/open-midinous-master/lib/midinous/proc_midi.rb:120:in `<top (required)>'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
	from /Users/andrei/Downloads/open-midinous-master/lib/midinous/init.rb:19:in `<top (required)>'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
	from /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/lib/ruby/2.6.0/rubygems/core_ext/kernel_require.rb:54:in `require'
	from midinous.rb:19:in `<main>'

I'm not sure if it's specific to midinous or unimid, would you please help? Sorry, I'm not an expert in Ruby and not sure where to look.