Problem on running Golden Sun 2 on GBA

Hi.. I'm new here.
I played in Golden Sun 1 before 2 weeks and I finished it..
Since than, I have been trying to find a good download to Golden Sun 2 with no success
I have on my computer about 40-50 bad Roms from different sites of this game that didn't work and I'm desperate..Every Rom that I'm trying to run on GBA work but the Roms for this game doesn't work
When I'm trying to run a rom for this game I see either a black screen or an error that says: unimplemented opcode 415bd621 from 742d1q5 (the numbers are changing every time)Sorry for my English I'm not from the US and I'm still learning..I hope you can help me and tell me what to do to run this game properly

that sounds more like the game uses a function in the hardware that has not been emulated.

Than what should I do to play this game ?

try a different emulator.