This is what the features menu of CormorantRoman.glyphs looks like now. «Update Features» or «Compile» does nothing. 
There’s not a single warning flag to be found in the features window, though:
How do I fix it?
How do I fix it?
This issue seems to be related to the latest release. Further discussion: Opentype features not previewing in G3
Thanks! And sorry for the redundant thread.
Is there an easy way to roll back while we wait…?
Export still works fine, it’s “just” the preview that doesn’t work. I think you can use an old version of Glyphs (e.g. 3045/3044) in the meantime or use a tool like FontGoggles for the preview. That is what I am doing anyway, since the build-in preview is constraint by the editing-workflow (positioning, normalization, etc. are not shown by the Glyphs feature preview since that would conflict with the edit view).
