When playing from an ISO or a blu ray folder image, I get an extra icon on the OSD that looks like an optical disk. Selecting that doesn’t seem to actually do anything - it doesn’t open any sort of settings window. Is that expected behaviour?
What skin are you using?
OSMC default skin.
The disc symbol on the right of the control bar of the video player OSD would normally direct you to the disc menu. The condition responsible for this should let the icon only show up, if there’s actually a disc menu to redirect you to. This seems to not work as expected at all times - it also shows up here when there’s no disc menu available. Then it does indeed, like you describe, not do anything when clicking on it. It’s a Kodi bug though.
In the case where we’re playing a blu ray image rather than a DVD, is there ever a viable menu to go to?
It would be logical to go to the title selection menu then, but you’re right: on platforms that can’t handle BD-J menus, many BD menus won’t be accessible properly. The condition used here is a general Kodi one that doesn’t seem to take into account that Kodi cannot render those menus on all platforms.