A small font with only a calt feature compiles fine but does not want to preview. There is a red exclamation mark in the bottom left corner. The same file in Glyphs 2 previews fine. (Build 3046)
Try the latest cutting edge version. For me, the red exclamation mark has been fixed in 3053. See also:
Suddenly, I have the same issue in 3.0.2 (3058). The problem persists, even after I delete all the features and have them updated.
3058 works for me. Could you share a screenshot of your features window? (File → Font Info… → Features)
Hm, looks good to me. You could try the latest cutting edge release of Glyphs (select Glyphs → Preferences… → Updates → Show cutting edge versions and click Check Now).