question about gm mode

[dgenerationx]

ok when ever i try to start a rivarly, i hit open, chose the storyline, and then chose a clean and dirty superstar. Then i do the lenght and all of that and i hit continue and something pops up saying something about a legend does not qualify for rivarlies. And they werent legends and i kept chosing different people and it kept saying the same thing.... does any one know????