GetRaidRosterInfo()

[Riraito]

im trying to make raid frames that display health mana etc and I've been using the following code:

        for i = 1,GetNumRaidMembers() do
            name, rank, subgroup, level, class, fileName, zone, online, isDead = GetRaidRosterInfo(i);
               .
               .
               .

and for the most part it works fine, but then randomly it just gives me the error on the code following that "attempt to index a nil value" so I'm wondering is there a better way to go about this?