When I use shapley2 in Stata, error report "Slow algorithm chosen. Try to increase matsize to enable the faster algorithm" when I choose 12 or more independent variables."

After a long waiting time, it then shows "Too many variables specified"

(the total number of variables I choose is less than 20)
I don't have any idea about how to solve it.
After a long waiting time, it then shows "Too many variables specified"
(the total number of variables I choose is less than 20)
I don't have any idea about how to solve it.
