guys please help me out

I really awnted to play HP half blood but the thing is i there a message that keeps popping up.......

What flashcart type and firmware do you use? What message do you get? If it has something to do with file saves, then you need to ARM7 patch it. See the common issues thread for details. :)

actually im using a no$gba emulator Ive played the HP 6 befere on my emulator but when I saved it was perfectly saved but then when I tried to load it, it says saved data could not be accessed please reinsert blah blah something like that....... pls help

you used the wrong save type then. Make sure you're using No$GBA 2.6a

You can find links to No$GBA 2.6a in the Common Issues thread.
https://www.romulation.org/forum/index.php?topic=1462.0