title: Auto Arima in R error: no seasonal differencing is selected
body: <p>I am working on creating a forecasting model for my company using the auto.arima package in R. </p>
  
  <p>Everytime I run the model get this error, and can't seem to find any resources on what to do about this</p>
  
  <pre><code>Warning in value[[3L]](cond): The chosen test encountered an error, so no seasonal differencing is selected. Check the time series data.
  </code></pre>
  
  <p>Does anyone know the meaning of this error? What do I check my time series data for? Any help would be greatly appreciated I have scoured the internet for answers on this and have came up with nothing. </p>
  
  <p>Here is the code I am using, I can't post data because it is confidential. But I have hundreds of time series of sales for different styles summarized by week</p>
  
  <pre><code>library(forecast)
  
  new &lt;- split(fctts, fctts$opt)
  
  mod1 &lt;- lapply(new, function(x) ts(x$sales, frequency = 52))
  
  mod &lt;- lapply(mod1, function(x) auto.arima(x))
  
  res &lt;- mapply(function(mod, new) forecast(mod, h = 12), mod, new)
  
  forecasts &lt;- lapply(apply(res,2,list), function(x) x[[1]]$mean)
  </code></pre>
  
  <p>SAMPLE DATA:</p>
  
  <pre><code>fctts &lt;- read.table(text='
  _week   opt sales 
  4/30/2017   Style_A 13
  5/7/2017    Style_A 13
  5/14/2017   Style_A 13
  5/21/2017   Style_A 12
  5/28/2017   Style_A 8
  6/4/2017    Style_A 17
  6/11/2017   Style_A 10
  6/18/2017   Style_A 8
  6/25/2017   Style_A 8
  7/2/2017    Style_A 10
  7/9/2017    Style_A 9
  7/16/2017   Style_A 11
  7/23/2017   Style_A 7
  7/30/2017   Style_A 5
  8/6/2017    Style_A 15
  8/13/2017   Style_A 23
  8/20/2017   Style_A 20
  8/27/2017   Style_A 24
  9/3/2017    Style_A 45
  9/10/2017   Style_A 39
  9/17/2017   Style_A 28
  9/24/2017   Style_A 22
  10/1/2017   Style_A 51
  10/8/2017   Style_A 43
  10/15/2017  Style_A 28
  10/22/2017  Style_A 30
  10/29/2017  Style_A 40
  11/5/2017   Style_A 14
  11/12/2017  Style_A 44
  11/19/2017  Style_A 14
  11/26/2017  Style_A 28
  12/3/2017   Style_A 31
  12/10/2017  Style_A 15
  12/17/2017  Style_A 23
  12/24/2017  Style_A 11
  12/31/2017  Style_A 12
  1/7/2018    Style_A 15
  1/14/2018   Style_A 21
  1/21/2018   Style_A 23
  1/28/2018   Style_A 20
  2/4/2018    Style_A 27
  2/11/2018   Style_A 33
  2/18/2018   Style_A 24
  2/25/2018   Style_A 31
  3/4/2018    Style_A 35
  3/11/2018   Style_A 19
  3/18/2018   Style_A 37
  3/25/2018   Style_A 47
  4/1/2018    Style_A 32
  4/8/2018    Style_A 52
  4/15/2018   Style_A 44
  4/22/2018   Style_A 33
  4/29/2018   Style_A 52
  5/6/2018    Style_A 31
  10/8/2017   Style_B 4
  10/15/2017  Style_B 4
  10/22/2017  Style_B 6
  10/29/2017  Style_B 8
  11/5/2017   Style_B 1
  11/12/2017  Style_B 7
  11/19/2017  Style_B 2
  11/26/2017  Style_B 2
  12/3/2017   Style_B 5
  12/10/2017  Style_B 1
  12/17/2017  Style_B 4
  12/24/2017  Style_B 3
  12/31/2017  Style_B 2
  1/7/2018    Style_B 7
  1/14/2018   Style_B 4
  1/21/2018   Style_B 10
  1/28/2018   Style_B 4
  2/4/2018    Style_B 8
  2/11/2018   Style_B 6
  2/18/2018   Style_B 9
  2/25/2018   Style_B 10
  3/4/2018    Style_B 18
  3/11/2018   Style_B 9
  3/18/2018   Style_B 14
  3/25/2018   Style_B 24
  4/1/2018    Style_B 5
  4/8/2018    Style_B 12
  4/15/2018   Style_B 9
  4/22/2018   Style_B 15
  4/29/2018   Style_B 16
  5/6/2018    Style_B 15
  4/30/2017   Style_C 7
  5/7/2017    Style_C 1
  5/14/2017   Style_C 0
  5/21/2017   Style_C 5
  5/28/2017   Style_C 1
  6/4/2017    Style_C 1
  6/11/2017   Style_C 5
  6/18/2017   Style_C 1
  6/25/2017   Style_C 1
  7/2/2017    Style_C 0
  7/9/2017    Style_C 2
  7/16/2017   Style_C 3
  7/23/2017   Style_C 6
  7/30/2017   Style_C 2
  8/6/2017    Style_C 5
  8/13/2017   Style_C 14
  8/20/2017   Style_C 7
  8/27/2017   Style_C 1
  9/3/2017    Style_C 1
  9/10/2017   Style_C 7
  9/17/2017   Style_C 0
  9/24/2017   Style_C 2
  10/1/2017   Style_C 5
  10/8/2017   Style_C 2
  10/15/2017  Style_C 0
  10/22/2017  Style_C 2
  10/29/2017  Style_C 1
  11/5/2017   Style_C 1
  11/12/2017  Style_C 1
  11/19/2017  Style_C 4
  11/26/2017  Style_C 13
  12/3/2017   Style_C 4
  12/10/2017  Style_C 7
  12/17/2017  Style_C 5
  12/24/2017  Style_C 2
  12/31/2017  Style_C 4
  1/7/2018    Style_C 6
  1/14/2018   Style_C 4
  1/21/2018   Style_C 7
  1/28/2018   Style_C 5
  2/4/2018    Style_C 19
  2/11/2018   Style_C 45
  2/18/2018   Style_C 33
  2/25/2018   Style_C 37
  3/4/2018    Style_C 36
  3/11/2018   Style_C 44
  3/18/2018   Style_C 22
  3/25/2018   Style_C 54
  4/1/2018    Style_C 35
  4/8/2018    Style_C 41
  4/15/2018   Style_C 26
  4/22/2018   Style_C 25
  4/29/2018   Style_C 52
  5/6/2018    Style_C 37
  ', header=TRUE)
  </code></pre>