When attempting to import data from an Excel spreadsheet using the JMP wizard I get this message "Cannot stack. Stacked columns are of different data type." What does it mean and how do I resolve the problem?
It means that you have the option "Treat multiple column header lines as hierarchies" checked, but the data types are not correct for that operation. JMP tries, with that option, to break out the header lines as separate columns where the data columns are paired with those separated header values. This is a similar operation to the Stack under the Tables menu.
Your error message is because the columns under the headers have different data types (character-vs-numeric) and can't be stacked.
You can avoid this error by turning off the "Treat multiple" option.