EXP Share?

[Vlash]

I'm kind of having trouble with the party setup. When I party with my friend (Exca) and try to set it to 'EXP Share', it says I can't modify the party. But I did it with another friend (Polaris) just fine.

Is Exca supposed to be a higher level or something? His base level is 23 and Job is 16 I think. My base level is 47 and Job is 35.

Can anyone tell me what the problem is?