Windows .ico requirements (SOLVED)

[sven]

Did you try with the settings described here?

App and window icon on Windows (DEF-3126) (SOLVED)

Managed to bundle a windows app with custom icon, both for binary and window; [18] Used this website (there are probably better ways to do it): http://icoconvert.com/ With these settings: [58]

I recall there was some issue with 256x256 size.