I have the same problem and I am experienced itch-user.
I can't mark that file is playable in browser, even at other projects I did it a lot multiple times. I tried to re-upload, double-checked hierarchy where index.html in the root of zip, but still can't see the checkmark. What could be the problem?
Yes, thank you, I found it in the end. But why I should to mark it, if regardless of this setting, I can mark downloadable Windows and macOS as well but not vice versa? And my game having both – downloadable and HTML... Seems like legacy part that allows to select even Flash and old Unity that is not supported by modern browsers. I just want to mark WebGL playable regardless of this setting, as I'm doing it for downloadable types.
