quantile function not working!

I am using Matlab2014b with the statistic toolbox (among others), and when I try to use the quantile function, it gives me an error message: Undefined function 'quantile' for input arguments of type 'double'. My numbers are obviously of type 'double', like the example provided in the 'Help' menu. Where is the problem?

[per isakson]

What does

    which quantile -all

return?