Unable to create classification models

[EVAUTOAI]

I am trying to build a classification model on iris dataset below is its description (column class2 is just a copy of the class column):

I am getting the below error:

[montanalow]

This is a dup of #1007. You'll need to update to update to master where this assertion has been converted to a more helpful error message.

[EVAUTOAI]

Ok, can you please help me understand how to do that?