[R] Zelig: Error message for 'mlogit'

[Mathew, Abraham T]

I'm running a multinomial logit in R using the Zelig package. However I get the following error. HELP


anes96two <- zelig(trade962a ~ age962 + education962 + personal962 + economy962 + partisan962 + employment962 + union962 + home962 + market962 + race962 + income962, model="mlogit", data=data96)


#Error in attr(tt, "depFactors")$depFactorVar :
#  $ operator is invalid for atomic vectors