As I’m working on a variable typeface with 20 styles, I see some trouble with opening them in either Font Book and Keynote. In Adobe they seems to work fine though.
Some instances and masters get recognised, while others do not really. Well, they are recognised, but gives them a generic name (In this case the’re all called ‘vars,’ see screenshot).
Let me explain: there are 10 instances (excluding obliques here) of which the ones starting with an underscore are the masters. The ones with the ++ are named wrong in Font Book and Keynote (also see screenshot below)
_Compressed 10 ++
Condensed 10 ++
_Regular 10
Extended 10
_Expanded 10