Our Midea AC runs all day but the cooling is weak and there's no error code, what's worth checking before we call someone?

'Runs fine, cools weakly, no code' is one of the most common AC calls, and on a Midea it's almost always airflow or capacity, not a failed component, which is exactly why nothing errors. Check in this order: the filters (clogged filters are the top cause, wash them), then the indoor coil and the outdoor unit (dust-caked coils in Dubai wreck efficiency), and airflow generally, furniture or a dirty blower dropping output. If all of that's clean and it still won't pull the room down, you're most likely low on refrigerant from a slow leak, or the coil needs a proper deep clean, and that's where it stops being DIY. Low gas especially won't throw a code on many units, it just under-cools and eventually ices up, so it gets misread as 'weak'. So do the filters and airflow first; if that doesn't fix it, book a proper AC coil and filter cleaning and a gas check rather than living with it, weak cooling that's left usually gets worse in peak heat.