Why does memory card slot 1 and 2 not work

I’ve had this problem once; it turned out to be lightly corroded contacts on the memory card itself. If you haven’t already, blow out the card, as well as the slot in the console, like you would an old NES cartridge. Another thing you should do is rub the card’s contacts with a rubbing alcohol-soaked q-tip. I imagine another possibility, if you’ve only tested either slot with the same card, is that the card has become corrupt either from age or from losing connection [either from dirty contacts or being nudged] while saving game data.

I have a new ps2 card and it still will not let me save my game on the screen it tells me I need 90KB of space to save kingdom harts game please if any body out there can tell me how I can fix this problem please let me know

Your current memory card is out of space.

Just by another memory card and insert into the other port.