GIF export bug - animation cuts and showing a blank screen

I’m trying to:
Export a prototype animation as a 800x600 GIF

But I can’t because:
The GIF export doesn’t work. It’s showing the first few frames and then it’s a blank screen.
The file weight seems to look fine and corresponds to the GIF animation length, but the animation is broken… Please advise.
Thanks, Ilya.

This impacts:
The ability to showcase work and get feedback.