I wonder how to solve the problem of factor outcome or class logical in the C5.0 model

Question

xdata <- credit_train[,-17]
ydata <- credit_train[,17]
treeModel <- C5.0(x=xdata,y=ydata)
Error: C5.0 models require a factor outcome

I specified it as a factor in the above error, but the following error occurred

xdata <- credit_train[,-17]
ydata <- as.factor(credit_train[,17])
treeModel <- C5.0(x=xdata,y=ydata)
Error in UseMethod("QuinlanAttributes") : 
no applicable method for 'QuinlanAttributes' 
applied to an object of class "logical"

After I set it logically, the following error occurs again. What else can I do?

xdata <- credit_train[,-17]
ydata <- as.logical(credit_train[,17])
treeModel <- C5.0(x=xdata,y=ydata)
Error: C5.0 models require a factor outcome