Glyps trial will not open

I downloaded the trial 14 days ago, but when I opened it today it looked like this:

I had to force quit it.

I tried to delete it and download it again, but the same thing happens.

When I try to download Glyphs mini trial, it works fine - what can I do to make it work again?

This can happen in El Capitan if a dialog box is still open. It can interfere with the redrawing of the window. Workaround: Pressing the Return key confirms the dialog, and everything else is back to normal again.