Hacking sd card menu problem

[shasta588]

I downloaded an injected wad of super smash bros. 64 and tried to install it useing wad manager but the only ios it will let me install it or any wads on is 249 or 250 otherwise I get an error and when I moved it to the sd card menu and tried to launch it I got an error that says "the system files sre corrupted please see the wii operations manual for instructions" or something like that. my question is did I do anything wrong or is it just incompatible with sd card menu. I have a softmoded 4.0 wii with softmii 2.9.5 installed. thanks in advance.