[R] library(forecast): Error in SD.test(x, m) : Insufficient data

[Jean Jacques Dureau]

I have these R code:

###########################################################################
time.test.data<-c(2.88645418326693, 2.91546949823027, 2.94130799329234,
  2.93313338038109, 2.89478957915832, 2.86029757243540, 2.78648486664669,
  2.80183167535133, 2.75435512226307, 2.78992352676563, 2.76028433151845,
  2.68741721854305, 2.70691974293828, 2.683833847881, 2.65041551246537,
  2.65169020111254, 2.58837541686517, 2.66549241844080, 2.58451314648945,
  2.60250871080139, 2.61253722876188, 2.59921041087878, 2.71727961060032,
  2.65440192667915, 2.74799149338374, 2.70649994101687, 2.80636027009366,
  2.81801086502298, 2.82555635319454, 2.87133347201997, 2.75746714456392,
  2.7660659236424, 2.71688375522241, 2.72655367231638, 2.72461997828447,
  2.78455790784558, 2.71160702495708, 2.65754456439869, 2.85673280918507,
  2.7053919591233, 2.7532637075718, 2.74272237196766, 2.75893306492199,
  2.62584686181772, 2.75230602278893, 2.82781018027572, 2.80220656652931,
  2.80242587601078, 2.84061953534849, 2.87123514783089, 2.76991605276683,
  2.77796934865900)

library(forecast)
auto.arima(ts(time.test.data, start=c(2011,1), frequency=52))
###########################################################################

I obtain the error message:
Error in SD.test(x, m) : Insufficient data

What is wrong?

jj