The information screen tells you about the current working state of the game within MAME. If you don't have the right files, I don't think MAME will even get to that screen.
What does the screen actually say? Give us a specific example from a game that you know is working. Maybe post a screenshot too.
Sorry for my late reply - I'm actually in the middle of building this computer from scratch again (CPU wasn't fast enough for some light gun games, and more advanced 3d games, so I upgraded and decided to reinstall Windows 10 just in case...which isn't going well lol). I'll be able to get back to this 12k+ game list once I figure out all that.
For which games, I may be confusing the red info screens, which commonly say something like 'emulation ok, sound issues', or when it boots up it says something like 'this ROM was not correctly dumped', or 'emulation isn't complete' (or something like that - even many green games which say 'ok, ok' for the status on the green info screen give me some errors or warnings when you launch them), but then the game STILL runs (sometimes REALLY bad, but sometimes with nothing I can see wrong with it - but maybe it'll crash once you've played it for a couple minutes - who knows).
I think this might simply be (my) user error with MAME's not-simple (and usually convoluted) user interface where I simply might not know what MAME
really means when it says some of these things, and the game really is OK to play (which could very well be why some of these which I was positive wouldn't work by the way MAME phrased a certain warning/caution, would STILL work). I'll get some specific examples and screenshots when I can as I'm sure I'm butchering these exact phrases I was quoting.