"Sort" on a List error after running boosting function



model.boosting.S1_tr_S <- boosting(Speeds ~.,data=S1_tr_S, boos = TRUE, mfinal=100)#
This is a boosting tree model.

Length Class Mode
formula 3 formula call
trees 100 -none- list
weights 100 -none- numeric
votes 2575 -none- numeric
prob 2575 -none- numeric
class 515 -none- character
importance 25 -none- numeric
terms 3 terms call
call 5 -none- call

boosting.pred.S1_te_S =predict(model.boosting.S1_tr_S ,newdata = S1_tr_S[1:25,], n.trees=600)

table(boosting.pred.S1_te_S, S1_te_S[,26])

ERROR (Below) after running table function
Error in sort.list(y) : 'x' must be atomic for 'sort.list'

Have you called 'sort' on a list?